Acoustic output apparatus and methods thereof

ABSTRACT

The present disclosure provides an acoustic output apparatus. The acoustic output apparatus may include an acoustic output component and a supporting structure forming an acoustically open structure that allows the acoustic output component to acoustically communicate with the surroundings. The acoustic output component may include a plurality of acoustic drivers, each of which may be configured to output a sound with a frequency range. At least one of the acoustic drivers may include a magnetic system for generating a first magnetic field. The magnetic system may include a first magnetic component for generating a second magnetic field and at least one second magnetic component. A magnetic gap may be formed between the first magnetic component and the at least one second magnetic component. A magnetic field intensity of the first magnetic field in the magnetic gap may be greater than that of the second magnetic field in the magnetic gap.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.17/170,947, filed on Feb. 9, 2021, which is a continuation ofInternational Application No. PCT/CN2020/084161, filed on Apr. 10, 2020,and claims priority to Chinese Patent Application No. 201910888067.6,filed on Sep. 19, 2019, Chinese Patent Application No. 201910888762.2,filed on Sep. 19, 2019, and Chinese Patent Application No.201910364346.2, filed on Apr. 30, 2019, the contents of each of whichare hereby incorporated by reference.

TECHNICAL FIELD

The present disclosure generally relates to acoustic devices, and moreparticularly, relates to an open acoustic output apparatus and methodsthereof.

BACKGROUND

With the development of acoustic technology, an acoustic outputapparatus has been widely used. An open binaural acoustic outputapparatus is a portable audio apparatus that facilitates soundconduction within a specific range of a user. In this case, the user mayhear sound in the ambient environment when the acoustic output apparatusdelivers sound (e.g., a piece of music, a news broadcast, a weatherforecast, etc.) to the user. However, an open structure of the openbinaural acoustic output apparatus may also lead to a sound leakage to acertain extent. Therefore, it is desirable to provide an acoustic outputapparatus and/or method for reducing sound leakage and enhancing soundfrom certain acoustic sources effectively, thereby improving an audioexperience of the user.

SUMMARY

According to an aspect of the present disclosure, an acoustic outputapparatus is provided. The acoustic output apparatus may include anacoustic output component and a supporting structure for supporting theacoustic output component proximate to a user's ear. The supportingstructure may form an acoustically open structure that allows theacoustic output component to acoustically communicate with thesurroundings. The acoustic output component may include a plurality ofacoustic drivers. Each of the plurality of acoustic drivers may beconfigured to output a sound with a frequency range. The frequencyranges of the sounds outputted by different acoustic dividers may bedifferent. At least one of the plurality of acoustic drivers may includea magnetic system for generating a first magnetic field. The magneticsystem may include a first magnetic component for generating a secondmagnetic field and at least one second magnetic component surroundingthe first magnetic component. A magnetic gap may be formed between thefirst magnetic component and the at least one second magnetic component.A magnetic field intensity of the first magnetic field in the magneticgap may be greater than that of the second magnetic field in themagnetic gap.

In some embodiments, the supporting structure may include an ear hookfor hanging the acoustic output component on the user's ear.

In some embodiments, the supporting structure may include a headbandplaced over the head of the user when the acoustic output apparatus isworn by the user.

In some embodiments, the supporting structure may include a fixingcomponent configured to fix the acoustic output component near anopening of an ear canal of the user. The fixing component may be placedinto the ear canal without blocking the ear canal.

In some embodiments, the plurality of acoustic drivers may include afirst acoustic driver configured to output a first sound with a firstfrequency range and a second acoustic driver configured to output asecond sound with a second frequency range. The second frequency rangemay include frequencies higher than the first frequency range.

In some embodiments, the supporting structure may include a plurality offirst sound guiding holes and a plurality of second sound guiding holes.The first sound may be outputted from the plurality of first soundguiding holes, and the second sound may be outputted from the pluralityof second sound guiding holes.

In some embodiments, the acoustic output apparatus may further include afirst acoustic route between the first acoustic driver and the pluralityof first sound guiding holes, and a second acoustic route between thesecond acoustic driver and the plurality of second sound guiding holes.The first acoustic route and the second acoustic route may havedifferent frequency selection characteristics.

In some embodiments, the plurality of first sound guiding holes mayinclude a pair of first sound guiding holes that are spaced apart fromeach other by a first distance. The plurality of second sound guidingholes may include a pair of second sound guiding holes that are spacedapart from each other by a second distance. The first distance may begreater than the second distance.

In some embodiments, the first distance may be in a range from 20 mm to40 mm, and the second distance may be in a range from 3 mm to 7 mm.

In some embodiments, at least one of the plurality of second soundguiding holes may be closer to an ear canal of the user than at leastone of the plurality of first sound guiding holes.

In some embodiments, the supporting structure may include a firsthousing for accommodating the first acoustic driver. The first housingmay include a first chamber and a second chamber located on either sideof the first acoustic driver.

In some embodiments, the first chamber may be acoustically coupled toone of the pair of first sound guiding holes. The second chamber may beacoustically coupled to the other one of the pair of first sound guidingholes.

In some embodiments, the supporting structure may include a secondhousing for accommodating the second acoustic driver. The second housingmay include a third chamber and a fourth chamber located on either sideof the second acoustic driver.

In some embodiments, the third chamber may be acoustically coupled toone of the pair of second sound guiding holes. The fourth chamber may beacoustically coupled to the other one of the pair of second soundguiding holes.

In some embodiments, the first sound may include a first portionoutputted from one of the pair of first sound guiding holes and a secondportion outputted from the other one of the pair of first sound guidingholes. The first portion may have an inversed phase with respect to thesecond portion.

In some embodiments, the first frequency range may include frequenciesbelow 650 Hz, and the second frequency range may include frequenciesabove 1000 Hz.

In some embodiments, the first frequency range and the second frequencyrange may overlap each other.

In some embodiments, the acoustic output apparatus may further include acontrol device configured to control the first acoustic driver and thesecond acoustic driver. The control device may include a frequencydivision module configured to divide a source signal into alow-frequency signal corresponding to the first frequency range fordriving the first acoustic driver to output the first sound and ahigh-frequency signal corresponding to the second frequency range fordriving the second acoustic driver to output the second sound.

In some embodiments, the frequency division module may include at leastone of a passive filter, an active filter, an analog filter, or adigital filter.

In some embodiments, the first acoustic driver may include a firstelectro-acoustic transducer. The second acoustic driver may include asecond electro-acoustic transducer. The first electro-acoustictransducer and the second electro-acoustic transducer may have differentfrequency responses.

In some embodiments, the magnetic system may further include a firstmagnetic conductive component mechanically connected to a first surfaceof the first magnetic component.

In some embodiments, the acoustic output apparatus may further include asecond magnetic conductive component mechanically connected to a secondsurface of the first magnetic component and at least one third magneticcomponent. The second surface may be opposite to the first surface ofthe first magnetic component. The at least one third magnetic componentmay be mechanically connected to each of the second magnetic conductivecomponent and the at least one second magnetic component.

In some embodiments, the acoustic output apparatus may further includeat least one fourth magnetic component placed within the magnetic gapand mechanically connected to each of the first magnetic component andthe second magnetic conductive component.

In some embodiments, the acoustic output apparatus may further includeat least one electric conductive component mechanically connected to atleast one of the first magnetic component, the first magnetic conductivecomponent, or the second magnetic conductive component.

In some embodiments, the acoustic output apparatus may further includeat least one of fifth magnetic component mechanically connected to thefirst magnetic conductive component. The at least one fifth magneticcomponent and the first magnetic component may be located at oppositesides of the first magnetic conductive component.

In some embodiments, the acoustic output apparatus may further include athird magnetic conductive component for suppressing a magnetic fieldleakage of the first magnetic field. The third magnetic conductivecomponent may be mechanically connected to the fifth magnetic component.The third magnetic conductive component and the first magneticconductive component may be located at opposite sides of the fifthmagnetic component.

In some embodiments, the acoustic output apparatus may further include amagnetic connector configured to charge the acoustic output apparatuswhen the magnetic connector absorbs a charging interface of an externalpower source.

In some embodiments, the magnetic connector may include a magneticadsorption ring, an insulation base, and a plurality of terminals. Theinsulation base may include a plurality of accommodation holes. At leastpart of the insulation base may be inserted into the magnetic adsorptionring. Each of the plurality of terminals may be accommodated in one ofthe plurality of accommodation holes.

In some embodiments, the insulation base may include a supporting memberand an insertion member. A cross section of the supporting member may begreater than that of the insertion member. The magnetic adsorption ringmay be inserted into an accommodation space formed by the supportingmember and the insertion member.

In some embodiments, the acoustic output apparatus may further include ahousing for accommodating the magnetic adsorption ring and theinsulation base.

In some embodiments, the housing may include a body and a flange at anend of the body. The body may be sleeved on the insulation base and themagnetic adsorption ring. The flange may cover an end of the magneticadsorption ring.

In some embodiments, an outer circumference wall of the supportingmember and an inner circumference wall of the body may be mechanicallyconnected via a buckle connection.

In some embodiments, the magnetic adsorption ring may have a shape of acircle, and each of the plurality of terminals may have a contractsurface that is concentric with the magnetic adsorption ring.

In some embodiments, the magnetic adsorption ring may be rotationalsymmetry with respect to a rotation center. A length of the magneticadsorption ring along a first direction may be different from a lengthof the magnetic adsorption ring along a second direction. The firstdirection and the second direction may be perpendicular to each other atthe rotation center.

In some embodiments, the magnetic adsorption ring may include aplurality of ring sections. At least one pair of adjacent ring sectionsof the plurality of ring sections may have different magnetic polaritiesat their respective end surfaces.

Additional features will be set forth in part in the description whichfollows, and in part will become apparent to those skilled in the artupon examination of the following and the accompanying drawings or maybe learned by production or operation of the examples. The features ofthe present disclosure may be realized and attained by practice or useof various aspects of the methodologies, instrumentalities andcombinations set forth in the detailed examples discussed below.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is further described in terms of exemplaryembodiments. These exemplary embodiments are described in detail withreference to the drawings. The drawings are not to scale. Theseembodiments are non-limiting exemplary embodiments, in which likereference numerals represent similar structures throughout the severalviews of the drawings, and wherein:

FIG. 1 is a schematic diagram illustrating an exemplary componentacoustic output apparatus according to some embodiments of the presentdisclosure;

FIG. 2A is a schematic diagram illustrating an exemplary acoustic outputapparatus according to some embodiments of the present disclosure;

FIG. 2B is a schematic diagram illustrating an exemplary acoustic outputapparatus according to some embodiments of the present disclosure;

FIG. 3 is a schematic diagram illustrating an exemplary acoustic outputapparatus according to some embodiments of the present disclosure;

FIG. 4 is a schematic diagram illustrating an exemplary acoustic outputapparatus according to some embodiments of the present disclosure;

FIG. 5 is a schematic diagram illustrating exemplary two point sourcesaccording to some embodiments of the present disclosure;

FIG. 6 is a schematic diagram illustrating a variation of a soundleakage of two point sources and a single point source along withfrequency according to some embodiments of the present disclosure;

FIGS. 7A-7B are graphs illustrating a volume of a near-field sound and avolume of a far-field leakage as a function of a distance between twopoint sources according to some embodiments of the present disclosure;

FIG. 8 is a schematic diagram illustrating an exemplary acoustic outputapparatus according to some embodiments of the present disclosure;

FIGS. 9A-9B are schematic diagrams illustrating exemplary applicationscenarios of an acoustic driver according to some embodiments of thepresent disclosure;

FIGS. 10A-10C are schematic diagrams illustrating exemplary sound outputscenarios according to some embodiments of the present disclosure;

FIGS. 11A-11B are schematic diagrams illustrating acoustic outputapparatuses according to some embodiments of the present disclosure;

FIGS. 12A-12C are schematic diagrams illustrating acoustic routesaccording to some embodiments of the present disclosure;

FIG. 13 is an exemplary graph illustrating a sound leakage under theaction of two sets of two point sources according to some embodiments ofthe present disclosure;

FIG. 14 is a schematic diagram illustrating another exemplary acousticoutput apparatus according to some embodiments of the presentdisclosure;

FIG. 15 is a schematic diagram illustrating two point sources andlistening positions according to some embodiments of the presentdisclosure

FIG. 16 is a graph illustrating a variation of a volume of a sound heardby a user of two point sources with different distances as a function ofa frequency of sound according to some embodiments of the presentdisclosure;

FIG. 17 is a graph illustrating a variation of a normalized parameter oftwo point sources in a far field along with a frequency of soundaccording to some embodiments of the present disclosure;

FIG. 18 is a distribution diagram illustrating an exemplary baffleprovided between two point sources according to some embodiments of thepresent disclosure;

FIG. 19 is a graph illustrating a variation of a volume of sound heardby a user as a function of a frequency of sound when an auricle islocated between two point sources according to some embodiments of thepresent disclosure;

FIG. 20 is a graph illustrating a variation of a volume of a leakedsound as a function of frequency when an auricle is located between twopoint sources according to some embodiments of the present disclosure;

FIG. 21 is a graph illustrating a variation of a normalized parameter asa function of frequency when two point sources of an acoustic outputapparatus are distributed on both sides of an auricle according to someembodiments of the present disclosure;

FIG. 22 is a graph illustrating a variation of a volume of sound heardby a user and a volume of a leaked sound as a function of frequency withand without a baffle between two point sources according to someembodiments of the present disclosure;

FIG. 23 is a graph illustrating a variation of a volume of sound heardby a user and a volume of a leaked sound as a function of the distancebetween two point sources at a frequency of 300 Hz and with or without abaffle according to some embodiments of the present disclosure;

FIG. 24 is a graph illustrating a variation of a volume of sound heardby a user and a volume of a leaked sound as a function of the distancebetween two point sources at a frequency of 1000 Hz and with or withouta baffle according to some embodiments of the present disclosure;

FIG. 25 is a graph illustrating a variation of a volume of sound heardby a user and a volume of a leaked sound as a function of distance at afrequency of 5000 Hz and with or without a baffle between the two pointsources according to some embodiments of the present disclosure;

FIG. 26 is a graph illustrating a variation of a volume of sound heardby the user as a function of frequency when a distanced of two pointsources is 1 cm according to some embodiments of the present disclosure;

FIG. 27 is a graph illustrating a variation of a volume of sound heardby the user as a function of frequency when a distanced of two pointsources is 2 cm according to some embodiments of the present disclosure;

FIG. 28 is a graph illustrating a variation of a normalized parameter asa function of frequency when a distanced of two point sources is 4 cmaccording to some embodiments of the present disclosure;

FIG. 29 is a graph illustrating a variation of a normalized parameter ofa far field as a function of the frequency of sound when the distancedof two point sources is 1 cm according to some embodiments of thepresent disclosure;

FIG. 30 is a graph illustrating a variation of a normalized parameter asa function of frequency when a distanced of two point sources is 2 cmaccording to some embodiments of the present disclosure;

FIG. 31 is a graph illustrating a variation of a normalized parameter asa function of frequency when a distanced of two point sources is 4 cmaccording to some embodiments of the present disclosure;

FIG. 32 is a graph illustrating exemplary distributions of differentlistening positions according to some embodiments of the presentdisclosure;

FIG. 33 is a graph illustrating a volume of sound heard by a user fromtwo point sources without baffle at different listening positions in anear field as a function of a frequency of sound according to someembodiments of the present disclosure;

FIG. 34 is a graph illustrating a normalized parameter of two pointsources without baffle at different listening positions in a near fieldaccording to some embodiments of the present disclosure;

FIG. 35 is a graph illustrating a volume of sound heard by a user fromtwo point sources with a baffle at different listening positions in anear field as a function of frequency according to some embodiments ofthe present disclosure;

FIG. 36 is a graph illustrating a normalized parameter of two pointsources with a baffle at different listening positions in a near fieldaccording to some embodiments of the present disclosure;

FIG. 37 is a schematic diagram illustrating two point sources and abaffle according to some embodiments of the present disclosure;

FIG. 38 is a graph illustrating a variation of a volume of a near-fieldsound as a function of a frequency of sound when a baffle is atdifferent positions according to some embodiments of the presentdisclosure;

FIG. 39 is a graph illustrating a variation of a volume of a far-fieldleakage as a function of a frequency of sound when a baffle is atdifferent positions according to some embodiments of the presentdisclosure;

FIG. 40 is a graph illustrating a variation of a normalization parameteras a function of a frequency of sound when a baffle is at differentpositions according to some embodiments of the present disclosure;

FIG. 41 is a schematic diagram illustrating another exemplary acousticoutput apparatus according to some embodiments of the presentdisclosure;

FIG. 42 is a schematic diagram illustrating a longitudinal sectionalview of an exemplary acoustic output apparatus according to someembodiments of the present disclosure;

FIG. 43 is a schematic diagram illustrating a longitudinal sectionalview of an exemplary magnetic system according to some embodiments ofthe present disclosure;

FIG. 44 is a schematic diagram illustrating a longitudinal sectionalview of an exemplary magnetic system according to some embodiments ofthe present disclosure;

FIG. 45 is a schematic diagram illustrating a longitudinal sectionalview of an exemplary magnetic system according to some embodiments ofthe present disclosure;

FIG. 46 is a schematic diagram illustrating a longitudinal sectionalview of an exemplary magnetic system according to some embodiments ofthe present disclosure;

FIG. 47 is a schematic diagram illustrating a longitudinal sectionalview of an exemplary magnetic system according to some embodiments ofthe present disclosure;

FIG. 48 illustrates an exploded view of a portion of an acoustic outputapparatus according to some embodiments of the present disclosure;

FIG. 49 illustrates a cross-sectional view of the portion of theacoustic output apparatus in FIG. 48 according to some embodiments ofthe present disclosure;

FIG. 50 illustrates a partially enlarged view of a portion A of themagnetic connector in FIG. 49 according to some embodiments of thepresent disclosure;

FIG. 51 is a schematic diagram illustrating a top view of an exemplarymagnetic connector according to some embodiments of the presentdisclosure;

FIG. 52 is a schematic diagram illustrating a top view of anotherexemplary magnetic connector according to some embodiments of thepresent disclosure; and

FIG. 53 is a schematic diagram illustrating a top view of anotherexemplary magnetic connector according to some embodiments of thepresent disclosure.

DETAILED DESCRIPTION

In order to illustrate the technical solutions related to theembodiments of the present disclosure, a brief introduction of thedrawings referred to in the description of the embodiments is providedbelow. Obviously, drawings described below are only some examples orembodiments of the present disclosure. Those having ordinary skills inthe art, without further creative efforts, may apply the presentdisclosure to other similar scenarios according to these drawings.Unless stated otherwise or obvious from the context, the same referencenumeral in the drawings refers to the same structure and operation.

As used in the disclosure and the appended claims, the singular forms“a,” “an,” and “the” include plural referents unless the content clearlydictates otherwise. It will be further understood that the terms“comprises,” “comprising,” “includes,” and/or “including” when used inthe disclosure, specify the presence of stated steps and elements, butdo not preclude the presence or addition of one or more other steps andelements.

Some modules of the system may be referred to in various ways accordingto some embodiments of the present disclosure, however, any number ofdifferent modules may be used and operated in a client terminal and/or aserver. These modules are intended to be illustrative, not intended tolimit the scope of the present disclosure. Different modules may be usedin different aspects of the system and method.

According to some embodiments of the present disclosure, flow charts areused to illustrate the operations performed by the system. It is to beexpressly understood, the operations above or below may or may not beimplemented in order. Conversely, the operations may be performed ininverted order, or simultaneously. Besides, one or more other operationsmay be added to the flowcharts, or one or more operations may be omittedfrom the flowchart.

Technical solutions of the embodiments of the present disclosure bedescribed with reference to the drawings as described below. It isobvious that the described embodiments are not exhaustive and are notlimiting. Other embodiments obtained, based on the embodiments set forthin the present disclosure, by those with ordinary skill in the artwithout any creative works are within the scope of the presentdisclosure.

FIG. 1 is a schematic diagram illustrating an exemplary acoustic outputapparatus 100 according to some embodiments of the present disclosure.As used herein, an acoustic output apparatus 100 refers to a devicehaving a sound output function. In practical applications, the acousticoutput apparatus 100 may be implemented by products of various types,such as an earphone, a bracelet, a glass, a helmet, a watch, clothing,or a backpack, or the like, or any combination thereof. For illustrationpurposes, an earphone with a sound output function may be provided as anexample of the acoustic output apparatus.

As shown in FIG. 1 , the acoustic output apparatus 100 may include ahousing 101, a power source 102, an acoustic driver 103, an acousticroute 105, and a sound guiding hole 106.

The housing 101 may be configured to protect one or more components ofthe acoustic output apparatus 100 (e.g., the power source 102, theacoustic driver 103, and/or the acoustic route 105). For example, thehousing 101 may form an accommodating space, and one or more componentsof the acoustic output apparatus 100 (e.g., the power source 102, theacoustic driver 103, the acoustic route 105) may be placed in theaccommodating space. In some embodiments, the housing 101 may includeone or more non-magnetic metal materials (e.g., copper, aluminum, and/oraluminum alloy), a plastic material, or the like, or any combinationthereof. The housing 101 may include one or more rigid materials and/orone or more soft materials.

In some embodiments, the housing 101 may include one or more componentsfor fixing the acoustic output apparatus 100 on, for example, an ear,the head, the shoulder, or the like, of a user who wears the acousticoutput apparatus 100. Merely by way of example, the housing 101 mayinclude a supporting structure for supporting an acoustic outputcomponent of the acoustic output apparatus 100 proximate to the user'sear. The acoustic output component of the acoustic output apparatus 100may include, for example, the acoustic driver 103 (or a portionthereof), the acoustic route 105, the sound guiding hole 106, or anyother component for generating and/or outputting sounds, any combinationthereof. In some embodiments, the supporting structure may form anacoustically open structure that allows the acoustic output component toacoustically communicate with the surroundings. The acoustic outputapparatus 100 that includes such supporting structure may be referred toas an open acoustic output apparatus. When worn by a user, the openacoustic output apparatus may not block the ear canal of the user andallow the user to listen to the sounds generated by the open acousticoutput apparatus and also the environment sound.

In some embodiments, the supporting structure may have any suitableform, shape, and/or size. Merely by way of example, the supportingstructure may include an ear hook for hanging the acoustic outputcomponent(s) on the user's ear. The ear hook may have a shape of, forexample, a circular ring, an oval, a polygonal (regular or irregular), aU-shape, a V-shape, a semi-circle, or the like. As another example, thesupporting structure may include a headband placed over the head of theuser when the acoustic output apparatus 100 is worn by the user. Theheadband may be completely rigid or completely flexible. Alternatively,a portion of the headband may be rigid and the other portion of theheadband may be flexible. As yet another example, the supportingstructure may include a fixing component configured to fix the acousticoutput component near an opening of an ear canal of the user, whereinthe fixing component may be placed into the ear canal without blockingthe ear canal. Merely by way of example, the fixing component may have ashape of a hollow circular ring matching the ear canal. When worn by theuser, the circular ring may be stuck in the ear canal without blockingthe ear cannel. More descriptions regarding the supporting structure maybe found elsewhere in the present disclosure. See, e.g., FIGS. 2A to 4and relevant descriptions thereof.

The power source 102 may be configured to provide an electrical power toone or more components of the acoustic output apparatus 100 (e.g., theacoustic driver 103). In some embodiments, the power source 102 mayinclude a circuit component, a battery, a charging interface, or thelike, or any combination thereof. The circuit component may beconfigured to connect the battery and one or more other components ofthe acoustic output apparatus 100 (e.g., the acoustic driver 103), andprovide power for operations of the other components. Exemplarybatteries may include but not limited to a storage battery, a drybattery, a lithium battery, or the like, or any combination thereof. Thecharging interface of the power source 102 may be used to charge theacoustic output apparatus 100 (e.g., the battery). In some embodiments,the charging interface of the power source 102 may include a magneticconnector configured to charge the acoustic output apparatus 100 whenthe magnetic connector absorbs a charging interface of an external powersource. More descriptions regarding the magnetic connector may be foundelsewhere in the present disclosure. See, e.g., FIGS. 48-53 and relevantdescriptions thereof.

The acoustic driver 103 may be configured to convert an electricalsignal into a sound. The acoustic driver 103 may be acoustically coupledwith the acoustic route 105 and the sound guiding hole 106. The soundgenerated by the acoustic driver 103 may be transmitted to the soundguiding hole 106 via the acoustic route 105, and the sound guiding hole106 may output the sound. In some embodiments, the acoustic driver 103may include a transducer (or referred to as an electro-acoustictransducer), such as an air conduction speaker, a bone conductionspeaker, a hydroacoustic transducer, an ultrasonic transducer, or thelike, or any combination thereof. The transducer may be of a moving coiltype, a moving iron type, a piezoelectric type, an electrostatic type, amagneto strictive type, or the like, or any combination thereof.

In some embodiments, the acoustic driver 103 may include a voice coil, avibration plate (e.g., a vibration diaphragm), and a magnetic system104. The magnetic system 104 may be configured to generate a magneticfield. When a current is applied to the voice coil, the ampere forcegenerated by the magnetic field may drive the voice coil to vibrate. Thevibration of the voice coil may drive the vibration plate to vibrate togenerate sound waves, which may be transmitted to the sound guiding hole106 through the acoustic route 105. In some embodiments, the magneticsystem 104 may include a magnetic component for generating a magneticfield and/or a magnetic conductive component for adjusting the magneticfield generated by the magnetic component. In some embodiments, themagnetic system 104 may include a plurality of magnetic components,which in combination may generate a total magnetic field. A magnetic gapmay be formed between the magnetic components (or portion thereof) ofthe magnetic system 104, and the voice coil may be placed in themagnetic gap. In the magnetic gap, the magnetic field intensity of thetotal magnetic field may be greater than that of the magnetic fieldgenerated by any individual magnetic component of the magnetic system104. More descriptions regarding an acoustic driver may be foundelsewhere in the present disclosure. See, e.g., FIG. 8 and relevantdescriptions thereof. More descriptions regarding a magnetic system maybe found elsewhere in the present disclosure. See, e.g., FIGS. 42 to 47and relevant descriptions thereof.

The acoustic route 105 may be configured to transmit a sound. Forexample, the acoustic route 105 may be acoustically coupled with theacoustic driver 103 and transmit a sound generated by the acousticdriver 103 to the sound guiding hole 106. In some embodiments, theacoustic route 105 may include a sound tube, a sound cavity, a resonancecavity, a sound hole, a sound slit, or a tuning net, or the like, or anycombination thereof. In some embodiments, the acoustic route 105 mayalso include an acoustic resistance material, which may have a specificacoustic impedance. Exemplary acoustic resistance materials may include,but not limited to, plastic, textile, metal, permeable material, wovenmaterial, screen material or mesh material, porous material, particulatematerial, polymer material, or the like, or any combination thereof.More descriptions regarding an acoustic route may be found elsewhere inthe present disclosure. See, e.g., FIG. 8 and relevant descriptionsthereof.

The sound guiding hole 106 be configured to propagate a sound, such asthe sound generated by the acoustic driver 103. In some embodiments, thesound guiding hole 106 may be formed on the housing 101 of the acousticoutput apparatus 100 with a specific opening and allowing sound to pass.Exemplary shapes of the sound guiding hole 106 may include a circleshape, an oval shape, a square shape, a trapezoid shape, a roundedquadrangle shape, a triangle shape, an irregular shape, or the like, orany combination thereof.

In some embodiments, the acoustic output apparatus 100 may include anycount of acoustic drivers 103, acoustic routes 105, and/or sound guidingholes 106. In some embodiments, the acoustic output apparatus 100 mayinclude a plurality of acoustic drivers 103, each of which is configuredto generate a sound with a specific frequency range. The soundsgenerated by different acoustic drivers 103 may have different frequencyranges. Optionally, the acoustic output apparatus 100 may furtherinclude a plurality of acoustic routes 105 and a plurality of pairs ofsound guiding holes 106. The sound generated by each of the acousticdrivers 103 may be transmitted to one pair of sound guiding holes 106via one of the acoustic routes 105. In some embodiments, parameter(s) ofthe acoustic drivers 103, the acoustic routes 105, and/or the pairs ofsound guiding holes 106 may be adjusted to improve the performance ofthe acoustic output apparatus 100, for example, reduce or eliminate theacoustic output apparatus's sound leakage to the environment and/orincrease the acoustic output apparatus's output effect to the user.

The description of the acoustic output apparatus 100 may be forillustration purposes, and not intended to limit the scope of thepresent disclosure. For those skilled in the art, various changes andmodifications may be made according to the description of the presentdisclosure. In some embodiments, the acoustic output apparatus 100 mayinclude one or more additional components and/or one or more componentsof the acoustic output apparatus 100 described above may be omitted. Forexample, the acoustic output apparatus 100 may include a storagecomponent for storing signals containing audio information. As anotherexample, the acoustic output apparatus 100 may include one or moreprocessors, which may execute one or more sound signal processingalgorithms for processing sound signals. Additionally or alternatively,two or more components of the acoustic output apparatus 100 may beintegrated into a single component. A component of the acoustic outputapparatus 100 may be implemented on two or more sub-components.

FIG. 2A is a schematic diagram illustrating an exemplary acoustic outputapparatus 200A according to some embodiments of the present disclosure.As shown in FIG. 2A, the acoustic output apparatus 200A may include atleast one circuit housing 210, two ear hooks 220, a rear hook 230, afirst speaker assembly 240 a, and a second speaker assembly 240 b. Acircuit housing 210 may be used to accommodate one or more components,such as a control circuit, a battery, or the like, or any combinationthereof, of the acoustic output apparatus 200A.

In some embodiments, the acoustic output apparatus 200A may include afirst circuit housing 210 a and a second circuit housing 210 b as shownin FIG. 2A. One of the two ear hooks 220 may be mechanically connectedto the first speaker assembly 240 a and the first circuit housing 210 a.The other one of the ear hooks 220 may be mechanically connected to thesecond speaker assembly 240 b and the second circuit housing 210 b. Theear hooks 220 may be used as a supporting structure of the acousticoutput apparatus 200A. For example, the shape of each of the ear hooks220 may match the shape of the user's ear. When the acoustic outputapparatus 200A is worn by the user, the ear hooks 220 may be hung on theuser's ears, and the rear hook 230 may surround the back of the user'shead. For example, the ear hook 220 a may be used to support the firstspeaker assembly 240 a approximate to the left ear of the user, and theear hook 220 b may be used to support the second speaker assembly 240 bapproximate to the right ear of the user. In some embodiments, the firstand second speaker assemblies may not block the ear canals of the user.

The speaker assemblies 240 a and 240 b may include one or more acousticoutput components for generating and/or output a sound, for example, anacoustic driver. In some embodiments, a plurality of components of theacoustic output apparatus 200A may form an integral assembly. In someembodiments, the acoustic output apparatus 200A may include one or moreadditional components and/or one or more components of the acousticoutput apparatus 200A may be omitted. For example, the acoustic outputapparatus 200A may include one or more user interaction elements, suchas one or more buttons, a microphone, a touch screen, or the like, forthe user to interact with the acoustic output apparatus 200A. As anotherexample, the rear hook 230 may be omitted, and the two ear hooks may beused independently.

In some embodiments, the acoustic output apparatus 200A may include oneor more sound guiding holes for outputting sounds. The count of thesound guiding holes may be any positive integer, such as 1, 2, 4, 5, 10,or the like. A sound guiding hole may be located at any position of theacoustic output apparatus 200A. Merely by way of example, a plurality ofsound guiding holes may be set on a housing of the speaker assembly 240a, wherein the sound guiding holes may be located on a same surface ordifferent surfaces of the speaker assembly 240 a. As another example, asound guiding hole may be located on the speaker assembly 240 a (e.g., asurface of the speaker assembly 240 a opposite to the first circuithousing 210 a), and another sound guiding hole may be located on thefirst circuit housing 210 a (e.g., a surface of the first circuithousing 210 a opposite to the speaker assembly 240 a). When the acousticoutput apparatus 200A is worn by the user, the sound guiding hole on thespeaker assembly 240 a and the sound guiding hole on the first circuithousing 210 a may be located on two sides of the user's auricle.

FIG. 2B is a schematic diagram illustrating an exemplary acoustic outputapparatus 200B according to some embodiments of the present disclosure.As shown in FIG. 2B, the acoustic output apparatus 200B may include anear hook 250, at least one sound guiding holes 260, and a speakerassembly (not shown in FIG. 2B). The ear hook 250 may have a shape of acircular ring, which may be hung on an ear of a user of the acousticoutput apparatus 200B. In some embodiments, an accommodation space maybe formed within the ear hook 250 for accommodating the speaker assembly(e.g., an acoustic driver).

The sound guiding hole(s) 260 may be set on a housing of the ear hook250. The count of the sound guiding hole(s) 260 may be any positivevalue. Merely by way of example, as shown in FIG. 2B, two sound guidingholes 260 may be set on a side of the ear hook 250 adjacent to the earcanal of the user, and one sound guiding hole 260 may be set on a sideof the ear hook 250 adjacent to the back of the ear. It should beunderstood that the acoustic output apparatus 200B in FIG. 2B isprovided for illustration purposes, and may be modified according toactual needs. For example, the ear hook 250 may have any other shapesuitable for human ears, for example, an oval, a polygonal (regular orirregular), a U-shape, a V-shape, a semi-circle, or the like. The atleast one sound guiding hole 260 may be located at any position on theacoustic output apparatus 200B.

FIG. 3 is a schematic diagram illustrating an exemplary acoustic outputapparatus 300 according to some embodiments of the present disclosure.As shown in FIG. 3 , the acoustic output apparatus 300 may have aheadband-shaped structure and include a housing 310, at least one soundguiding hole 320 (e.g., a first sound guiding hole 320-1, a second soundguiding hole 320-2, a third sound guiding hole 320-3, and a fourth soundguiding hole 320-4), and a speaker assembly (not shown in FIG. 3 ). Thehousing 310 may have a shape of a headband and include at least a sidesurface 312 and at least an end surface 314. The acoustic outputapparatus 300 may be placed over the head or the neck of a user when theacoustic output apparatus 300 is worn by the user.

The at least one sound guiding hole 320 may be located at the housing310. Merely by way of example, the first sound guiding hole 320-1 may belocated at the end surface 314. The second sound guiding hole 320-2, thethird sound guiding hole 320-3, and the fourth sound guiding hole 320-4may be located at the side surface 312. Different sound guiding holes320 may have a same shape or different shapes. In some embodiments,different sound guiding holes 320 may be used output sounds withdifferent frequency ranges. Merely by way of example, the sound guidingholes 320-1 and 320-2 may be used to output low-frequency sounds (e.g.,a sound with a frequency lower than a threshold frequency), and thesound guiding holes 320-3 and 320-4 may be used output high frequencysounds (e.g., a sound with a frequency higher than the thresholdfrequency). The distance between the sound guiding holes 320-1 and 320-2and/or the distance between the sound guiding holes 320-3 and 320-4 maybe adjusted to achieve an improved performance of the acoustic outputapparatus 300, such as a reduced sound leakage to the environment and/oran improved sound output effect at the user's ears.

FIG. 4 is a schematic diagram illustrating an exemplary acoustic outputapparatus 400 according to some embodiments of the present disclosure.The acoustic output apparatus 400 may include a housing 410, a fixingcomponent 420, and a speaker assembly (not shown in FIG. 4 )accommodated within the housing 410. In some embodiments, the speakerassembly of the acoustic output apparatus 400 may be mechanicallyconnected to the fixing component 240 and placed proximate to an openingof the ear canal by the fixing component 240. The fixing component 240may have a shape matching the ear canal of the user and can be fixed inthe ear canal. The fixing component 240 may have a through-hole throughwhich the air can pass when it is fixed in the ear canal. In someembodiments, the fixing component 240 may include one or more softmaterials (e.g., soft silicone, rubber, etc.) so that it may becomfortable to wear. In some embodiments, one or more sound guidingholes may be set on the housing 410. For example, a sound guiding holemay be set on a portion of the housing 410 adjacent to the ear canal ofthe user, and another sound guiding hole may be set on a portion of thehousing 410 adjacent to the back of the ear of the user.

It should be noted that the examples illustrated in FIGS. 2A to 4 aremerely provided for the purposes of illustration, and not intended tolimit the scope of the present disclosure. For persons having ordinaryskills in the art, multiple variations and modifications may be madeunder the teachings of the present disclosure. However, those variationsand modifications do not depart from the scope of the presentdisclosure. For example, the shape, size, and/or position of a componentof an acoustic output apparatus may be adjusted according to an actualneed.

FIG. 5 is a schematic diagram illustrating an exemplary two pointsources according to some embodiments of the present disclosure. Inorder to further explain the effect of the setting of the sound guidingholes on the acoustic output apparatus, and considering that the soundmay be regarded as propagating outwards from the sound guiding holes,the present disclosure may describe sound guiding holes on an acousticoutput apparatus as sound sources for externally outputting sound.

Just for the convenience of description and for the purpose ofillustration, when sizes of the sound guiding holes on the acousticoutput apparatus are small, each sound guiding hole may be approximatelyregarded as a point source (or referred to as a point sound source or asound source). In some embodiments, any sound guiding hole provided onthe acoustic output apparatus for outputting sound may be approximatedas a single point (sound) source on the acoustic output apparatus. Thesound field pressure p generated by a single point source may satisfyEquation (1):

$\begin{matrix}{{p = {\frac{{j\omega\rho}_{0}}{4\pi\; r}Q_{0}\exp\mspace{14mu}{j\left( {{\omega\; t} - {kr}} \right)}}},} & (1)\end{matrix}$where ω denotes an angular frequency, ρ₀ denotes an air density, rdenotes a distance between a target point and the point source, Q₀denotes a volume velocity of the point source, and k denotes the wavenumber. It may be concluded that the magnitude of the sound fieldpressure of the point source at the target point is inverselyproportional to the distance from the target point to the point source.

It should be noted that the sound guiding holes for outputting sound aspoint sources may only serve as an explanation of the principle andeffect of the present disclosure, and may not limit the shapes and sizesof the sound guiding holes in practical applications. In someembodiments, if an area of a sound guiding hole is large enough, thesound guiding hole may also be equivalent to a planar acoustic source.In some embodiments, the point source may also be realized by otherstructures, such as a vibration surface and a sound radiation surface.For those skilled in the art, without creative activities, it may beknown that sounds produced by structures such as a sound guiding hole, avibration surface, and an acoustic radiation surface may be similar to apoint source at the spatial scale discussed in the present disclosure,and may have similar sound propagation characteristics and the similarmathematical description method. Further, for those skilled in the art,without creative activities, it may be known that the acoustic effectachieved by “an acoustic driver may output sound from at least two firstsound guiding holes” described in the present disclosure may alsoachieve the same effect by other acoustic structures, for example, “atleast two acoustic drivers each may output sound from at least oneacoustic radiation surface.” According to actual situations, otheracoustic structures may be selected for adjustment and combination, andthe same acoustic output effect may also be achieved. The principle ofradiating sound outward with structures such as surface sound sourcesmay be similar to that of point sources, and may not be repeated here.

As mentioned above, at least two sound guiding holes corresponding to asame acoustic driver may be set on the acoustic output apparatusprovided in the specification. In this case, two point sources may beformed, which may reduce sound transmitted to the surroundingenvironment. For convenience, sound output from the acoustic outputapparatus to the surrounding environment may be referred to as afar-field leakage since it can be heard by others in the environment.The sound output from the acoustic output apparatus to the ears of theuser wearing the acoustic output apparatus may be referred to as anear-field sound since a distance between the acoustic output apparatusand the user is relatively short. In some embodiments, the sound outputfrom two sound guiding holes (i.e., two point sources) may have acertain phase difference. When the distance between the two pointsources and the phase difference of the two point sources meet a certaincondition, the acoustic output apparatus may output different soundeffects in the near field (for example, the position of the user's ear)and the far field. For example, if the phases of the point sourcescorresponding to the two sound guiding holes are opposite, that is, anabsolute value of the phase difference between the two point sources is180 degrees, the far-field leakage may be reduced according to theprinciple of reversed phase cancellation. More details regarding anenhancement of the acoustic output apparatus by adjusting the amplitudeand/or phase of each point source may be found in Internationalapplication No. PCT/CN2019/130884, filed on Dec. 31, 2019, the entirecontent of which may be hereby incorporated by reference.

As shown in FIG. 5 , a sound field pressure p generated by two pointsources may satisfy Equation (2):

$\begin{matrix}{{p = {{\frac{A_{1}}{r_{1}}\exp\mspace{14mu}{j\left( {{\omega\; t} - {kr_{1}} + \varphi_{1}} \right)}} + {\frac{A_{2}}{r_{2}}\exp\mspace{14mu}{j\left( {{\omega t} - {kr_{2}} + \varphi_{2}} \right)}}}},} & (2)\end{matrix}$where A₁ and A₂ denote intensities of the two point sources, and φ₁ andφ₂ denote phases of the two point sources, respectively, d denotes adistance between the two point sources, and r₁ and r₂ may satisfyEquation (3):

$\begin{matrix}\left\{ {\begin{matrix}{r_{1} = \sqrt{r^{2} + \left( \frac{d}{2} \right)^{2} - {2*r*\frac{d}{2}*\cos\mspace{14mu}\theta}}} \\{r_{2} = \sqrt{r^{2} + \left( \frac{d}{2} \right)^{2} + {2*r*\frac{d}{2}*\cos\mspace{14mu}\theta}}}\end{matrix},} \right. & (3)\end{matrix}$where r denotes a distance between a target point and the center of thetwo point sources in the space, and θ indicates an angle between a lineconnecting the target point and the center of the two point sources andthe line on which the two point source is located.

It may be concluded from Equation (3) that a magnitude of the soundpressure pat the target point in the sound field may relate to theintensity of each point source, the distance d, the phase of each pointsource, and the distance r.

Two point sources with different output effects may be achieved bydifferent settings of sound guiding holes, such that the volume of thenear-field sound may be improved, and the far-field leakage may bereduced. For example, an acoustic driver may include a vibrationdiaphragm. When the vibration diaphragm vibrates, sounds may betransmitted from the front and rear sides of the vibration diaphragm,respectively. The front side of the vibration diaphragm in the acousticoutput apparatus may be provided with a front chamber for transmittingsound. The front chamber may be coupled with a sound guiding holeacoustically. The sound on the front side of the vibration diaphragm maybe transmitted to the sound guiding hole through the front chamber andfurther transmitted outwards. The rear side of the vibration diaphragmin the acoustic output apparatus may be provided with a rear chamber fortransmitting sound. The rear chamber may be coupled with another soundguiding hole acoustically. The sound on the rear side of the vibrationdiaphragm may be transmitted to the sound guiding hole through the rearchamber and propagate further outwards. It should be noted that, whenthe vibration diaphragm is vibrating, the front side and the rear sideof the vibration diaphragm may generate sounds with opposite phases. Insome embodiments, the structures of the front chamber and rear chambermay be specially set so that the sound output by the acoustic driver atdifferent sound guiding holes may meet a specific condition. Forexample, lengths of the front chamber and rear chamber may be speciallydesigned such that sounds with a specific phase relationship (e.g.,opposite phases) may be output at the two sound guiding holes. As aresult, a problem that the acoustic output apparatus has a low volume inthe near-field and a sound leakage in the far-field may be effectivelyresolved.

Under certain conditions, compared to the volume of a far-field leakageof a single point source, the volume of a far-field leakage of two pointsources may increase with the frequency. In other words, the leakagereduction capability of the two point sources in the far field maydecrease with the frequency increases. For further description, a curveillustrating a relationship between a far-field leakage and a frequencymay be described in connection with FIG. 6 .

FIG. 6 is a schematic diagram illustrating a variation of a soundleakage of two point sources and a single point source as a function offrequency according to some embodiments of the present disclosure. Thedistance between the two point sources in FIG. 6 may be fixed, and thetwo point sources may have a substantially same amplitude and oppositephases. The dotted line may indicate a variation curve of a volume of aleaked sound of the single point source at different frequencies. Thesolid line may indicate a variation curve of a volume of a leaked soundof the two point sources at different frequencies. The abscissa of thediagram may represent the sound frequency (f), and the unit may be Hertz(Hz). The ordinate of the diagram may use a normalization parameter α toevaluate the volume of a leaked sound. The parameter α may be determinedaccording to Equation (4):

$\begin{matrix}{{\alpha = \frac{\left| P_{far} \right|^{2}}{\left| P_{ear} \right|^{2}}},} & (4)\end{matrix}$where P_(far) represents the sound pressure of the acoustic outputapparatus in the far-field (i.e., the sound pressure of the far-fieldsound leakage). P_(ear) represents the sound pressure around the user'sears (i.e., the sound pressure of the near-field sound). The larger thevalue of a, the larger the far-field leakage relative to the near-fieldsound heard will be, indicating that a poorer capability of the acousticoutput apparatus for reducing the far-field leakage.

As shown in FIG. 6 , when the frequency is below 6000 Hz, the far-fieldleakage produced by the two point sources may be less than the far-fieldleakage produced by the single point source, and may increase as thefrequency increases. When the frequency is close to 10000 Hz (forexample, about 8000 Hz or above), the far-field leakage produced by thetwo point sources may be greater than the far-field leakage produced bythe single point source. In some embodiments, a frequency correspondingto an intersection of the variation curves of the two point sources andthe single point source may be determined as an upper limit frequencythat the two point sources are capable of reducing a sound leakage.

For illustrative purposes, when the frequency is relatively small (forexample, in a range of 100 Hz-1000 Hz), the capability of reducing asound leakage of the two point sources may be strong (e.g., the value ofa is small, such as below −80 dB). In such a frequency band, an increaseof the volume of the sound heard by the user may be determined as anoptimization goal. When the frequency is larger (for example, in a rangeof 1000 Hz˜8000 Hz), the capability of reducing a sound leakage of thetwo point sources may be weak (e.g., above −80 dB). In such a frequencyband, a decrease of the sound leakage may be determined as theoptimization goal.

According to FIG. 6 , it may be possible to determine a frequencydivision point based on the variation tendency of the two point sources'capability of reducing a sound leakage. Parameters of the two pointsources may be adjusted according to the frequency division point so asto reducing the sound leakage of the acoustic output apparatus. Forexample, the frequency corresponding to a of a specific value (forexample, −60 dB, −70 dB, −80 dB, −90 dB, etc.) may be used as thefrequency division point. Parameters of the two point sources may bedetermined to improve the near-field sound in a frequency band below thefrequency division point, and/or to reduce the far-field sound leakagein a frequency band above the frequency division point. In someembodiments, a high-frequency band with a high frequency (for example, asound output from a high-frequency acoustic driver) and a low-frequencyband with a low frequency (for example, a sound output from alow-frequency acoustic driver) may be determined based on the frequencydivision point. More details of the frequency division point may bedisclosed elsewhere in the present disclosure, for example, FIG. 8 andthe descriptions thereof.

In some embodiments, the method for measuring and determining the soundleakage may be adjusted according to the actual conditions. For example,a plurality of points on a spherical surface centered by s center pointof the two point sources with a radius of r (for example, 40 centimeter)may be identified, and an average value of amplitudes of the soundpressure at the plurality of points may be determined as the value ofthe sound leakage. The distance between the near-field listeningposition and the point sources may be far less than the distance betweenthe point sources and the spherical surface for measuring the far-fieldleakage. Optionally, the ratio of the distance from the near-fieldlistening position to the center of the two point sources to the radiusr may be less than 0.3, 0.2, 0.15, or 0.1. As another example, one ormore points of the far-field may be taken as the position for measuringthe sound leakage, and the sound volume of the position may be taken asthe value of the sound leakage. As another example, a center of the twopoint sources may be used as a center of a circle at the far field, andsound pressure amplitudes of two or more points evenly distributed atthe circle according to a certain spatial angle may be averaged as thevalue of the sound leakage. These methods may be adjusted by thoseskilled in the art according to actual conditions, and is not intendedto be limiting.

According to FIG. 6 , it may be concluded that in the high-frequencyband (a higher frequency band determined according to the frequencydivision point), the two point sources may have a weak capability toreduce a sound leakage. In the low-frequency band (a lower frequencyband determined according to the frequency division point), the twopoint sources may have a strong capability to reduce a sound leakage. Ata certain sound frequency, if the distance between the two point sourceschanges, its capability to reduce a sound leakage may be changed, andthe difference between volume of the sound heard by the user (alsoreferred to as “heard sound”) and volume of the leaked sound may also bechanged. For a better description, the curve of a far-field leakage as afunction of the distance between the two point sources may be describedwith reference to FIGS. 7A and 7B.

FIGS. 7A and 7B are exemplary graphs illustrating a volume of anear-field sound and a volume of a far-field leakage as a function of adistance between two point sources according to some embodiments of thepresent disclosure. FIG. 7B may be generated by performing anormalization on the graph in FIG. 7A.

In FIG. 7A, a solid line may represent a variation curve of the volumeof the two point sources as a function of the distance between the twopoint sources, and the dotted line may represent the variation curve ofthe volume of the leaked sound of the two point sources as a function ofthe distance between the two point sources. The abscissa may represent adistance ratio d/d0 of the distanced of the two point sources to areference distance d0. The ordinate may represent a sound volume (theunit is decibel dB). The distance ratio d/d0 may reflect a variation ofthe distance between the two point sources. In some embodiments, thereference distance d0 may be selected within a specific range. Forexample, d0 may be a specific value in the range of 2.5 mm-10 mm, e.g.,d0 may be 5 mm. In some embodiments, the reference distance d0 may bedetermined based on a listening position. For example, the distancebetween the listening position to the nearest point source may be takenas the reference distance d0. It should be known that the referencedistance d0 may be flexibly selected from any other suitable valuesaccording to the actual conditions, which is not limited here. Merely byway of example, in FIG. 7A, d0 may be 5 mm.

When the sound frequency is a constant, the volume of the sound heard bythe user and volume of the leaked sound of the two point sources mayincrease as the distance between the two point sources increases. Whenthe distance ratio d/d0 of is less than a threshold ratio, an increase(or increment) in the volume of the sound heard by the user may belarger than an increase (or increment) in the volume of the leaked soundas the distance between two point sources increases. That is to say, theincrease in volume of the sound heard by the user may be moresignificant than the increase in volume of the leaked sound. Forexample, as shown in FIG. 7A, when the distance ratio d/d0 is 2, thedifference between the volume of the sound heard by the user and thevolume of the leaked sound may be about 20 dB. When the distance ratiod/d0 is 4, the difference between the volume of the sound heard by theuser and the volume of the leaked sound may be about 25 dB. In someembodiments, when the distance ratio d/d0 reaches the threshold ratio,the ratio of the volume of the sound heard by the user to the volume ofthe leaked sound of the two point sources may reach a maximum value. Atthis time, as the distance of the two point sources further increases,the curve of the volume of the sound heard by the user and the curve ofthe volume of the leaked sound may gradually go parallel, that is, theincrease in volume of the sound heard by the user and the increase involume of the leaked sound may remain substantially the same. Forexample, as shown in FIG. 7B, when the distance ratio d/d0 is 5, 6, or7, the difference between the volume of the sound heard by the user andthe volume of the leaked sound may remain substantially the same, bothof which may be about 25 dB. That is, the increase in volume of thesound heard by the user may be the same as the increase in volume of theleaked sound. In some embodiments, the threshold ratio of the distanceratio d/d0 of the two point sources may be in the range of 0-7. Forexample, the threshold ratio of d/d0 may be set in the range of 0.5-4.5.As another example, the threshold ratio of d/d0 may be set in the rangeof 1-4.

In some embodiments, the threshold ratio value may be determined basedon the variation of the difference between the volume of the sound heardby the user and the volume of the leaked sound of the two point sourcesof FIG. 7A. For example, the ratio corresponding to the maximumdifference between the volume of the sound heard by the user and thevolume of the leaked sound may be determined as the threshold ratio. Asshown in FIG. 7B, when the distance ratio d/d0 is less than thethreshold ratio (e.g., 4), a curve of a normalized sound heard by theuser (also referred to as “normalized heard sound”) may show an upwardtrend (the slope of the curve is larger than 0) as the distance betweenthe two point sources increases. That is, the increase in sound heard bythe user volume may be greater than the increase in volume of the leakedsound. When the distance ratio d/d0 is greater than the threshold ratio,the slope of the curve of the normalized sound heard by the user maygradually approach 0 as the distance between the two point sourcesincreases. That is to say, the increase in volume of the sound heard bythe user may be no longer greater than the increase in volume of theleaked sound as the distance between the two point sources increases.

According to the descriptions above, if the listening position is fixed,the parameters of the two point sources may be adjusted by certainmeans. It may be possible to achieve an effect that the volume of thenear-field sound has a significant increase while the volume of thefar-field leakage only increases slightly (i.e., the increase in thevolume of the near-field sound is greater than the volume of thefar-field leakage). For example, two or more sets of two point sources(such as a set of high-frequency two point sources and a set oflow-frequency two point sources) may be used. For each set, the distancebetween the point sources in the set are adjusted by a certain means, sothat the distance between the high-frequency two point sources may beless than the distance between the low-frequency two point sources. Thelow-frequency two point sources may have a small sound leakage (thecapability to reduce the sound leakage is strong), and thehigh-frequency two point sources have a large sound leakage (thecapability to reduce the sound leakage is weak). The volume of the soundheard by the user may be significantly larger than the volume of theleaked sound if a smaller distance between the two point sources is setin the high-frequency band, thereby reducing the sound leakage.

In some embodiments, each acoustic driver may have a corresponding pairof sound guiding holes. The distance between the sound guiding holescorresponding to each acoustic driver may affect the volume of thenear-field sound transmitted to the user's ears and the volume of thefar-field leakage transmitted to the environment. In some embodiments,if the distance between the sound guiding holes corresponding to ahigh-frequency acoustic driver is less than that between the soundguiding holes corresponding to a low-frequency acoustic driver, thevolume of the sound heard by the user may be increased and the soundleakage may be reduced, thereby preventing the sound from being heard byothers near the user of the acoustic output apparatus. According to theabove descriptions, the acoustic output apparatus may be effectivelyused as an open earphone even in a relatively quiet environment.

FIG. 8 is a schematic diagram illustrating an exemplary acoustic outputapparatus according to some embodiments of the present disclosure. Asshown in FIG. 8 , the acoustic output apparatus 800 may include anelectronic frequency division module 810, an acoustic driver 840, anacoustic driver 850, an acoustic route 845, an acoustic route 855, atleast two first sound guiding holes 847, and at least two second soundguiding holes 857. In some embodiments, the acoustic output apparatus800 may further include a controller (not shown in the figure). Theelectronic frequency division module 810 may be part of the controllerand configured to generate electrical signals that are input intodifferent acoustic drivers. The connection between different componentsin the acoustic output apparatus 800 may be wired and/or wireless. Forexample, the electronic frequency division module 810 may send signalsto the acoustic driver 840 and/or the acoustic driver 850 through awired transmission or a wireless transmission.

The electronic frequency division module 810 may divide the frequency ofa source signal. The source signal may come from one or more soundsource apparatus (for example, a memory storing audio data). The soundsource apparatus may be part of the acoustic output apparatus 800 or anindependent device. The source signal may be an audio signal that isreceived by the acoustic output apparatus 800 via a wired or wirelessmeans. In some embodiments, the electronic frequency division module 810may decompose the source signal into two or more frequency-dividedsignals having different frequencies. For example, the electronicfrequency division module 110 may decompose the source signal into afirst frequency-divided signal (or frequency-divided signal 1) having ahigh-frequency sound and a second frequency-divided signal (orfrequency-divided signal 2) having a low-frequency sound. Forconvenience, a frequency-divided signal having the high-frequency soundmay be referred to as a high-frequency signal, and a frequency-dividedsignal having the low-frequency sound may be referred to as alow-frequency signal.

For the purposes of description, a low-frequency signal described in thepresent disclosure may refer to a sound signal with a frequency in afirst frequency range (or referred to as a low frequency range). Ahigh-frequency signal may refer to a sound signal with a frequency in asecond frequency range (or referred to as a high frequency range). Thefirst frequency range and the second frequency range may or may notinclude overlapping frequency ranges. The second frequency range mayinclude frequencies higher than the first frequency range. Merely by wayof example, the first frequency range may include frequencies below afirst threshold frequency. The second frequency range may includefrequencies above a second threshold frequency. The first thresholdfrequency may be lower than the second threshold frequency, or equal tothe second threshold frequency, or higher than the second thresholdfrequency. For example, the first threshold frequency may be lower thanthe second threshold frequency (for example, the first thresholdfrequency may be 600 Hz and the second threshold frequency may be 700Hz), which means that there is no overlap between the first frequencyrange and the second frequency range. As another example, the firstthreshold frequency may be equal to the second frequency (for example,both the first threshold frequency and the second threshold frequencymay be 650 Hz or any other frequency values). As another example, thefirst threshold frequency may be higher than the second thresholdfrequency, which indicates that there is an overlap between the firstfrequency range and the second frequency range. In such cases, in someembodiments, the difference between the first threshold frequency andthe second threshold frequency may not exceed a third thresholdfrequency. The third threshold frequency may be a fixed value, forexample, 20 Hz, 50 Hz, 100 Hz, 150 Hz, or 200 Hz. Optionally, the thirdthreshold frequency may be a value related to the first thresholdfrequency and/or the second threshold frequency (for example, 5%, 10%,15%, etc., of the first threshold frequency). Alternatively, the thirdthreshold frequency may be a value flexibly set by the user according tothe actual needs, which may be not limited herein. It should be notedthat the first threshold frequency and the second threshold frequencymay be flexibly set according to different situations, and are notlimited herein.

In some embodiments, the electronic frequency division module 810 mayinclude a frequency divider 815, a signal processor 820, and a signalprocessor 830. The frequency divider 815 may be used to decompose thesource signal into two or more frequency-divided signals containingdifferent frequency components, for example, a frequency-divided signal1 having a high-frequency sound component and a frequency-divided signal2 having a low-frequency sound component. In some embodiments, thefrequency divider 815 may be any electronic device that may implementthe signal decomposition function, including but not limited to one of apassive filter, an active filter, an analog filter, a digital filter, orany combination thereof. In some embodiments, the frequency divider 815may divide the source signal based on one or more frequency divisionpoints. A frequency division point may refer to a specific frequencydistinguishing the first frequency range and the second frequency range.For example, when there is an overlapping frequency range between thefirst frequency range and the second frequency range, the frequencydivision point may be a feature point within the overlapping frequencyrange (for example, a low-frequency boundary point, a high-frequencyboundary point, a center frequency point, etc., of the overlappingfrequency range). In some embodiments, the frequency division point maybe determined according to a relationship between the frequency and thesound leakage of the acoustic output apparatus (for example, the curvesshown in FIGS. 6, 7A, and 7B). For example, considering that the soundleakage of the acoustic output apparatus changes with the frequency, afrequency point corresponding to the volume of the leaked soundsatisfying a certain condition may be selected as the frequency divisionpoint, for example, 1000 Hz shown in FIG. 6 . In some alternativeembodiments, the user may specify a specific frequency as the frequencydivision point directly. For example, considering that the frequencyrange of sounds that the human ear may hear is 20 Hz-20 kHz, the usermay select a frequency point in this range as the frequency divisionpoint. For example, the frequency division point may be 600 Hz, 800 Hz,1000 Hz, 1200 Hz, or the like. In some embodiments, the frequencydivision point may be determined based on the performance of theacoustic drivers 840 and 850. For example, considering that alow-frequency acoustic driver and a high-frequency acoustic driver havedifferent frequency response curves, the frequency division point may beselected within a frequency range. The frequency range may be above ½ ofthe upper limiting frequency of the low-frequency acoustic driver andbelow 2 times of the lower limiting frequency of the high-frequencyacoustic driver. In some embodiments, the frequency division point maybe selected in a frequency range above ⅓ of the upper limiting frequencyof the low-frequency acoustic driver and below 1.5 times of the lowerlimiting frequency of the high-frequency acoustic driver. In someembodiments, in the overlapping frequency range, the positionalrelationship between point sources may also affect the volume of thesound produced by the acoustic output apparatus in the near field andthe far field. More details may be found in International applicationNo. PCT/CN2019/130886, filed on Dec. 31, 2019, the entire contents ofwhich are hereby incorporated by reference.

The signal processor 820 and the signal processor 830 may furtherprocess a frequency-divided signal to meet the requirements of soundoutput. In some embodiments, the signal processor 820 and/or the signalprocessor 830 may include one or more signal processing components. Forexample, the signal processing components(s) may include, but notlimited to, an amplifier, an amplitude modulator, a phase modulator, adelayer, a dynamic gain controller, or the like, or any combinationthereof. Merely by way of example, the processing of a sound signal bythe signal processor 820 and/or the signal processor 830 may includeadjusting the amplitude of a portion of the sound signal that has aspecific frequency. In some embodiments, if the first frequency rangeand the second frequency range overlap, the signal processors 820 and830 may adjust the intensity of a portion of a sound signal that has thefrequency in the overlapping frequency range (for example, reduce theamplitude of the portion that has the frequency in the overlappingfrequency range). This may avoid that in a final sound outputted byacoustic output apparatus, the portion that corresponds to theoverlapping frequency range may have an excessive volume caused by thesuperposition of multiple sound signals.

After being processed by the signal processors 820 or 830, thefrequency-divided signals 1 and 2 may be transmitted to the acousticdrivers 840 and 850, respectively. In some embodiments, the processedfrequency-divided signal transmitted into the acoustic driver 840 may bea sound signal having a lower frequency range (e.g., the first frequencyrange). Therefore, the acoustic driver 840 may also be referred to as alow-frequency acoustic driver. The processed frequency-dividedtransmitted into the acoustic driver 850 may be a sound signal having ahigher frequency range (e.g., the second frequency range). Therefore,the acoustic driver 850 may also be referred to as a high-frequencyacoustic driver. The acoustic driver 840 and the acoustic driver 850 mayconvert sound signals into a low-frequency sound and a high-frequencysound, respectively, then propagate the converted signals outwards.

In some embodiments, the acoustic driver 840 may be acoustically coupledto at least two first sound guiding holes. For example, the acousticdriver 840 may be acoustically coupled to the two first sound guidingholes 847 via two acoustic routes 845. The acoustic driver 840 maypropagate sound through the at least two first sound guiding holes 847.The acoustic driver 850 may be acoustically coupled to at least twosecond sound guiding holes. For example, the acoustic driver 850 may beacoustically coupled to the two second sound guiding holes 857 via twoacoustic routes 855. The acoustic driver 850 may propagate sound throughthe at least two second sound guiding holes 857. A sound guiding holemay be a small hole formed on the acoustic output apparatus with aspecific opening and allowing sound to pass. The shape of a soundguiding hole may include but not limited to a circle shape, an ovalshape, a square shape, a trapezoid shape, a rounded quadrangle shape, atriangle shape, an irregular shape, or the like, or any combinationthereof. In addition, the number of the sound guiding holes connected tothe acoustic driver 840 or 850 may not be limited to two, which may bean arbitrary value instead, for example, three, four, six, or the like.

In some embodiments, in order to reduce the far-field leakage of theacoustic output apparatus 800, the acoustic driver 840 may be used tooutput low-frequency sounds with the same (or approximately the same)amplitude and opposite (or approximately opposite) phases via the atleast two first sound guiding holes. The acoustic driver 850 may be usedto output high-frequency sounds with the same (or approximately thesame) amplitude and opposite (or approximately opposite) phases via theat least two second sound guiding holes. In this way, the far-fieldleakage of low-frequency sounds (or high-frequency sounds) may bereduced according to the principle of acoustic interferencecancellation.

According to FIGS. 6 7A and 7B, considering that the wavelength of alow-frequency sound is longer than that of a high-frequency sound, andin order to reduce the interference cancellation of the sound in thenear field (for example, near the user's ear), the distance between thefirst sound guiding holes and the distance between the second soundguiding holes may have different values. For example, assuming thatthere is a first distance between the two first sound guiding holes anda second distance between the two second sound guiding holes, the firstdistance may be longer than the second distance. In some embodiments,the first distance and the second distance may be arbitrary values.Merely by way of example, the first distance may not be longer than 40mm, for example, in the range of 20 mm-40 mm. The second distance maynot be longer than 12 mm, and the first distance may be longer than thesecond distance. In some embodiments, the first distance may not beshorter than 12 mm. The second distance may be shorter than 7 mm, forexample, in the range of 3 mm-7 mm. In some embodiments, the firstdistance may be 30 mm, and the second distance may be 5 mm. As anotherexample, the first distance may be at least twice longer than the seconddistance. In some embodiments, the first distance may be at least threetimes longer than the second distance. In some embodiments, the firstdistance may be at least 5 times longer than the second distance.

As shown in FIG. 8 , the acoustic driver 840 may include a transducer843. The transducer 843 may transmit a sound to the first sound guidinghole(s) 847 through the acoustic route 845. The acoustic driver 850 mayinclude a transducer 853. The transducer 853 may transmit a sound to thesecond sound guiding hole(s) 857 through the acoustic route 855. In someembodiments, the transducer may include, but not limited to, atransducer of a gas-conducting acoustic output apparatus, a transducerof a bone-conducting acoustic output apparatus, a hydroacoustictransducer, an ultrasonic transducer, or the like, or any combinationthereof. In some embodiments, the transducer may be of a moving coiltype, a moving iron type, a piezoelectric type, an electrostatic type,or a magneto strictive type, or the like, or any combination thereof.

In some embodiments, the acoustic drivers (such as the low-frequencyacoustic driver 840, the high-frequency acoustic driver 850) may includetransducers with different properties or different counts oftransducers. For example, each of the low-frequency acoustic driver 840and the high-frequency acoustic driver 850 may include a transducer, andthe transducers of the frequency acoustic driver 840 and thehigh-frequency acoustic driver 850 may have different frequency responsecharacteristics (such as a low-frequency speaker unit and ahigh-frequency speaker unit). As another example, the low-frequencyacoustic driver 840 may include two transducers 843 (such as twolow-frequency speaker units), and the high-frequency acoustic driver 850may include two transducers 853 (such as two high-frequency speakerunits).

In some embodiments, the acoustic output apparatus 800 may generatesounds with different frequency ranges by other means, for example, atransducer frequency division, an acoustic route frequency division, orthe like. When the acoustic output apparatus 800 uses a transducer or anacoustic route to divide a sound, the electronic frequency divisionmodule 810 (e.g., the part inside the dotted frame in FIG. 8 ) may beomitted. The source signal may be input to the acoustic driver 840 andthe acoustic driver 850, respectively.

In some embodiments, the acoustic output apparatus 800 may use aplurality of transducers to achieve signal frequency division. Forexample, the acoustic driver 840 and the acoustic driver 850 may convertthe inputted source signal into a low-frequency signal and ahigh-frequency signal, respectively. Specifically, through thetransducer 843 (such as a low-frequency speaker), the low-frequencyacoustic driver 840 may convert the source signal into the low-frequencysound having a low-frequency component. The low-frequency sound may betransmitted to at least two first sound guiding holes 847 along at leasttwo different acoustic routes 845. Then the low-frequency sound may bepropagated outwards through the first sound guiding holes 847. Throughthe transducer 853 (such as a high-frequency speaker), thehigh-frequency acoustic driver 850 may convert the source signal intothe high-frequency sound having a high-frequency component. Thehigh-frequency sound may be transmitted to at least two second soundguiding holes 857 along at least two different acoustic routes 855. Thenthe high-frequency sound may be propagated outwards through the secondsound guiding holes 857.

In some alternative embodiments, an acoustic route (e.g., the acousticroutes 845 and the acoustic routes 855) connecting a transducer and asound guiding hole may affect the nature of the transmitted sound. Forexample, an acoustic route may attenuate or change the phase of thetransmitted sound to some extent. In some embodiments, the acousticroute may include a sound tube, a sound cavity, a resonance cavity, asound hole, a sound slit, a tuning net, or the like, or any combinationthereof. In some embodiments, the acoustic route may include an acousticresistance material, which may have a specific acoustic impedance. Forexample, the acoustic impedance may be in the range of SMKS Rayleigh to500MKS Rayleigh. Exemplary acoustic resistance materials may include butnot limited to plastic, textile, metal, permeable material, wovenmaterial, screen material or mesh material, porous material, particulatematerial, polymer material, or the like, or any combination thereof. Bysetting acoustic routes of different acoustic impedances, the soundsoutput of different transducers may be acoustically filtered. In thiscase, the sounds output through different acoustic routes have differentfrequency components.

In some embodiments, the acoustic output apparatus 800 may utilize aplurality of acoustic routes to achieve signal frequency division.Specifically, the source signal may be inputted into a specific acousticdriver and converted into a sound including high and low-frequencycomponents. The sound may be propagated along an acoustic route having aspecific frequency selection characteristic. For example, the sound maybe propagated along an acoustic route with a low-pass characteristic toa corresponding sound guiding hole to output a low-frequency sound. Inthis process, the high-frequency component of the sound may be absorbedor attenuated by the acoustic route with a low-pass characteristic.Similarly, the sound signal may be propagated along an acoustic routewith a high-pass characteristic to the corresponding sound guiding holeto output a high-frequency sound. In this process, the low-frequencycomponent of the sound may be absorbed or attenuated by the acousticroute with the high-pass characteristic.

In some embodiments, the controller in the acoustic output apparatus 800may cause the low-frequency acoustic driver 840 to output a sound in thefirst frequency range (i.e., a low-frequency sound), and cause thehigh-frequency acoustic driver 850 to output a sound in the secondfrequency range (i.e., a high-frequency sound). In some embodiments, theacoustic output apparatus 800 may also include a supporting structure.The supporting structure may be used to carry an acoustic driver (suchas the high-frequency acoustic driver 850, the low-frequency acousticdriver 840), so that the acoustic driver may be positioned away from theuser's ear. In some embodiments, the sound guiding hole(s) acousticallycoupled with the high-frequency acoustic driver 850 may be locatedcloser to an expected position of the user's ears (for example, the earcanal entrance), while the sound guiding hole(s) acoustically coupledwith the low-frequency acoustic driver 840 may be located further awayfrom the expected position. In some embodiments, the supportingstructure may be used to package the acoustic driver. For example, thesupporting structure may include a casing made of various materials suchas plastic, metal, and tape. The casing may encapsulate the acousticdriver and form a front chamber and a rear chamber corresponding to theacoustic driver. The front chamber may be acoustically coupled to one ofthe at least two sound guiding holes corresponding to the acousticdriver. The rear chamber may be acoustically coupled to the other of theat least two sound guiding holes corresponding to the acoustic driver.For example, the front chamber of the low-frequency acoustic driver 840may be acoustically coupled to one of the at least two first soundguiding holes 847. The rear chamber of the low-frequency acoustic driver840 may be acoustically coupled to the other of the at least two firstsound guiding holes 847. The front chamber of the high-frequencyacoustic driver 850 may be acoustically coupled to one of the at leasttwo second sound guiding holes 857. The rear chamber of thehigh-frequency acoustic driver 850 may be acoustically coupled to theother of the at least two second sound guiding holes 857. In someembodiments, a sound guiding hole (such as the first sound guidinghole(s) 847 and the second sound guiding hole(s) 857) may be disposed onthe casing.

The above description of the acoustic output apparatus 800 may be merelyprovided by way of example. Those skilled in the art may makeadjustments and changes to the structure, quantity, etc., of theacoustic driver, which is not limiting in the present disclosure. Insome embodiments, the acoustic output apparatus 800 may include anynumber of the acoustic drivers. For example, the acoustic outputapparatus 800 may include two groups of the high-frequency acousticdrivers 850 and two groups of the low-frequency acoustic drivers 840, orone group of the high-frequency acoustic drives 850 and two groups ofthe low-frequency acoustic drivers 840, and thesehigh-frequency/low-frequency drivers may be used to generate a sound ina specific frequency range, respectively. As another example, theacoustic driver 840 and/or the acoustic driver 850 may include anadditional signal processor. The signal processor may have the samestructural component as or different structural component from thesignal processor 820 or 830.

It should be noted that the acoustic output apparatus and its modulesshown in FIG. 8 may be implemented in various ways. For example, in someembodiments, the system and the modules may be implemented by hardware,software, or a combination of both. The hardware may be implemented by adedicated logic. The software may be stored in a storage which may beexecuted by a suitable instruction execution system, for example, amicroprocessor or a dedicated design hardware. It will be appreciated bythose skilled in the art that the above methods and systems may beimplemented by computer-executable instructions and/or embedded incontrol codes of a processor. For example, the control codes may beprovided by a medium such as a disk, a CD or a DVD-ROM, a programmablememory device, such as read-only memory (e.g., firmware), or a datacarrier such as an optical or electric signal carrier. The system andthe modules in the present disclosure may be implemented not only by ahardware circuit in a programmable hardware device in an ultra largescale integrated circuit, a gate array chip, a semiconductor such alogic chip or a transistor, a field programmable gate array, or aprogrammable logic device. The system and the modules in the presentdisclosure may also be implemented by a software to be performed byvarious processors, and further also by a combination of hardware andsoftware (e.g., firmware).

It should be noted that the above description of the acoustic outputapparatus 800 and its components is only for convenience of description,and not intended to limit the scope of the present disclosure. It may beunderstood that, for those skilled in the art, after understanding theprinciple of the apparatus, it is possible to combine each unit or forma substructure to connect with other units arbitrarily without departingfrom this principle. For example, the electronic frequency divisionmodule 810 may be omitted, and the frequency division of the sourcesignal may be implemented by the internal structure of the low-frequencyacoustic driver 840 and/or the high-frequency acoustic driver 850. Asanother example, the signal processor 820 or 830 may be a partindependent of the electronic frequency division module 810. Thosemodifications may fall within the scope of the present disclosure.

FIGS. 9A and 9B are schematic diagrams illustrating exemplary acousticoutput apparatuses according to some embodiments of the presentdisclosure. For the purpose of illustration, sounds outputted bydifferent sound guiding holes coupled with a same transducer may bedescribed as an example. In FIGS. 9A and 9B, each transducer may have afront side and a rear side, and a front chamber and a rear chamber mayexist on the front and rear side of the transducer, respectively. Insome embodiments, these structures may have the same or approximatelythe same equivalent acoustic impedance, such that the transducer may beloaded symmetrically. The symmetrical load of the transducer may formsound sources satisfying an amplitude and phase relationship atdifferent sound guiding holes (such as the “two point sources” having asame amplitude and opposite phases as described above), such that aspecific sound field may be formed in the high-frequency range and/orthe low-frequency range (for example, the near-field sound may beenhanced and the far-field leakage may be suppressed).

As shown in FIGS. 9A and 9B, an acoustic driver (for example, theacoustic driver 910 or 920) may include transducers, and acoustic routesand sound guiding holes connected to the transducers. In order todescribe an actual application scenario of the acoustic output apparatusmore clearly, a position of a user's ear E is shown in FIGS. 9A and 9Bfor explanation. FIG. 9A illustrates an application scenario of theacoustic driver 910. The acoustic driver 910 may include a transducer943 (or referred to as a low-frequency acoustic driver), and thetransducer 943 may be coupled with two first sound guiding holes 947through an acoustic route 945. FIG. 9B illustrates an applicationscenario of the acoustic driver 920. The acoustic driver 920 may includea transducer 953 (or referred to as a high-frequency acoustic driver),and the transducer 953 may be coupled with two second sound guidingholes 957 through an acoustic route 955.

The transducer 943 or 953 may vibrate under the driving of an electricsignal, and the vibration may generate sounds with equal amplitudes andopposite phases (180 degrees inversion). The type of the transducer mayinclude, but not limited to, an air conduction speaker, a boneconduction speaker, a hydroacoustic transducer, an ultrasonictransducer, or the like, or any combination thereof. The transducer maybe of a moving coil type, a moving iron type, a piezoelectric type, anelectrostatic type, a magneto strictive type, or the like, or anycombination thereof. In some embodiments, the transducer 943 or 953 mayinclude a vibration diaphragm, which may vibrate when driven by anelectrical signal, and the front and rear sides of the vibrationdiaphragm may simultaneously output a normal-phase sound and areverse-phase sound. In FIGS. 9A and 9B, “+” and “−” may be used torepresent sounds with different phases, wherein “+” may represent anormal-phase sound, and “−” may represent a reverse-phase sound.

In some embodiments, a transducer may be encapsulated by a casing of asupporting structure, and the interior of the casing may be providedwith sound channels connected to the front and rear sides of thetransducer, respectively, thereby forming an acoustic route. Forexample, a front cavity of the transducer 943 may be coupled to one ofthe two first sound guiding holes 947 through a first acoustic route(i.e., a half of the acoustic route 945), and a rear cavity of thetransducer 943 may acoustically be coupled to the other sound guidinghole of the two first sound guiding holes 947 through a second acousticroute (i.e., the other half of the acoustic route 945). A normal-phasesound and a reverse-phase sound output from the transducer 943 may beoutput from the two first sound guiding holes 947, respectively. Asanother example, a front cavity of the transducer 953 may be coupled toone of the two sound guiding holes 957 through a third acoustic route(i.e., half of the acoustic route 955), and a rear cavity of thetransducer 953 may be coupled to another sound guiding hole of the twosecond sound guiding holes 957 through a fourth acoustic route (i.e.,the other half of the acoustic route 955). A normal-phase sound and areverse-phase sound output from the transducer 953 may be output fromthe two second sound guiding holes 957, respectively.

In some embodiments, an acoustic route may affect the nature of thetransmitted sound. For example, an acoustic route may attenuate orchange the phase of the transmitted sound to some extent. In someembodiments, the acoustic route may include one or more of a sound tube,a sound cavity, a resonance cavity, a sound hole, a sound slit, a tuningnet, or the like, or any combination thereof. In some embodiments, theacoustic route may include an acoustic resistance material, which mayhave a specific acoustic impedance. For example, the acoustic impedancemay be in the range of SMKS Rayleigh to 500MKS Rayleigh. In someembodiments, the acoustic resistance material may include but notlimited to plastics, textiles, metals, permeable materials, wovenmaterials, screen materials, and mesh materials, or the like, or anycombination thereof. In some embodiments, in order to prevent the soundtransmitted by the acoustic driver's front chamber and rear chamber frombeing differently disturbed, the front chamber and rear chambercorresponding to the acoustic driver may have the approximately sameequivalent acoustic impedance. Additionally, sound guiding holes withthe same acoustic resistance material, the same size and/or shape, etc.,may be used.

The distance between the two first sound guiding holes 947 of thelow-frequency acoustic driver may be expressed as d1 (i.e., the firstdistance). The distance between the two second sound guiding holes 957of the high-frequency acoustic driver may be expressed as d2 (i.e., thesecond distance). By setting the distances d1 and d2, a higher soundvolume output in the low-frequency band and a stronger ability to reducethe sound leakage in the high-frequency band may be achieved. Forexample, the distance between the two first sound guiding holes 947 isgreater than the distance between the two second sound guiding holes 957(i.e., d1>d2).

In some embodiments, the transducer 943 and the transducer 953 may behoused together in a housing of an acoustic output apparatus, and beplaced in isolation in a structure of the housing.

In some embodiments, the acoustic output apparatus may include multiplesets of high-frequency acoustic drivers and low-frequency acousticdrivers. For example, the acoustic output apparatus may include a set ofhigh-frequency acoustic drivers and a set of low-frequency acousticdrivers for simultaneously outputting sound to the left and/or rightears. As another example, the acoustic output apparatus may include twosets of high-frequency acoustic drivers and two sets of low-frequencyacoustic drivers, wherein one set of high-frequency acoustic drivers andone set of low-frequency acoustic drivers may be used to output sound toa user's left ear, and the other set of high-frequency acoustic driversand the other set of low-frequency acoustic drivers may be used tooutput sound to a user's right ear.

In some embodiments, the high-frequency acoustic driver and thelow-frequency acoustic driver may have different powers. In someembodiments, the low-frequency acoustic driver may have a first power,the high-frequency acoustic driver may have a second power, and thefirst power may be greater than the second power. In some embodiments,the first power and the second power may be arbitrary values.

FIGS. 10A, 10B, and 10C are schematic diagrams illustrating sound outputscenarios according to some embodiments of the present disclosure.

In some embodiments, the acoustic output apparatus may generate soundsin the same frequency range through two or more transducers, and thesounds may propagate outwards through different sound guiding holes. Insome embodiments, different transducers may be controlled by the samecontroller or different controllers, respectively, and may producesounds that satisfy a certain phase and amplitude condition (forexample, sounds with the same amplitude but opposite phases, sounds withdifferent amplitudes and opposite phases, etc.). For example, acontroller may make the electrical signals input into two low-frequencytransducers of an acoustic driver have the same amplitude and oppositephases. In this way, the two low-frequency transducers may outputlow-frequency sounds with the same amplitude but opposite phases.

Specifically, the two transducers in an acoustic driver (such as alow-frequency acoustic driver 1010 or a high-frequency acoustic driver1020) may be arranged side by side in an acoustic output apparatus, oneof which may be used to output a normal-phase sound, and the other maybe used to output a reverse-phase sound. As shown in FIG. 10A, theacoustic driver 1010 may include two transducers 1043, two acousticroutes 1045, and two first sound guiding holes 1047. As shown in FIG.10B, the acoustic driver 1050 may include two transducers 1053, twoacoustic routes 1055, and two second sound guiding holes 1057. Driven byelectrical signals with opposite phases, the two transducers 1043 maygenerate a set of low-frequency sounds with opposite phases (180 degreesinversion). One of the two transducers 1043 (such as the transducerlocated below) may output a normal-phase sound, and the other (such asthe transducer located above) may output a reverse-phase sound. The twolow-frequency sounds with opposite phases may be transmitted to the twofirst sound guiding holes 1047 along the two acoustic routes 1045,respectively, and propagate outwards through the two first sound guidingholes 1047. Similarly, driven by electrical signals with oppositephases, the two transducers 1053 may generate a set of high-frequencysounds with opposite phases (180 degrees inversion). One of the twotransducers 1053 (such as the transducer located below) may output anormal-phase high-frequency sound, and the other (such as the transducerlocated above) may output a reverse-phase high-frequency sound. Thehigh-frequency sounds with opposite phases may be transmitted to the twosecond sound guiding holes 1057 along the two acoustic routes 1055,respectively, and propagate outwards through the two second soundguiding holes 1057.

In some embodiments, the two transducers in an acoustic driver (forexample, the low-frequency acoustic driver 1043 and the high-frequencyacoustic driver 1053) may be arranged relatively close to each otheralong a straight line, and one of them may be used to output anormal-phase sound and the other may be used to output a reverse-phasesound.

As shown in FIG. 10C, the left side may be the acoustic driver 1010, andthe right side may be the acoustic driver 1020. The two transducers 1043of the acoustic driver 1010 may generate a set of low-frequency soundsof equal amplitude and opposite phases under the control of thecontroller, respectively. One of the transducers 1043 may output anormal-phase low-frequency sound, and transmit the normal-phaselow-frequency sound along a first acoustic route to a first soundguiding hole 1047. The other transducer 1043 may output a reverse-phaselow-frequency sound, and transmit the reverse-phase low-frequency soundalong a second acoustic route to another first sound guiding hole 1047.The two transducers 1053 of the acoustic driver 1020 may generatehigh-frequency sounds of equal amplitude and opposite phases under thecontrol of the controller, respectively. One of the transducers 1053 mayoutput a normal-phase high-frequency sound, and transmit thenormal-phase high-frequency sound along a third acoustic route to asecond sound guiding hole 1057. The other transducer 1053 may output areverse-phase high-frequency sound, and transmit the reverse-phasehigh-frequency sound along a fourth acoustic route to another secondsound guiding hole 1057.

In some embodiments, the transducer 1043 and/or the transducer 1053 maybe of various suitable types. For example, the transducer 1043 and thetransducer 1053 may be dynamic coil speakers, which may have thecharacteristics of a high sensitivity in low-frequency, a deep lowfrequency depth, and a small distortion. As another example, thetransducer 1043 and the transducer 1053 may be moving iron speakers,which may have the characteristics of a small size, a high sensitivity,and a large high-frequency range. As another example, the transducers1043 and 1053 may be air-conducted speakers or bone-conducted speakers.As yet another example, the transducer 1043 and the transducer 1053 maybe balanced armature speakers. In some embodiments, the transducer 1043and the transducer 1053 may be of different types. For example, thetransducer 1043 may be a moving iron speaker, and the transducer 1053may be a moving coil speaker. As another example, the transducer 1043may be a dynamic coil speaker, and the transducer 1053 may be a movingiron speaker.

In FIGS. 10A-10C, the distance between the two point sources of theacoustic driver 1010 may be d1, the distance between the two pointsources of the acoustic driver 1020 may be d2, and d1 may be greaterthan d2. As shown in FIG. 10C, the listening position (that is, theposition of the ear canal when the user wears an acoustic outputapparatus) may be approximately located on a line of a set of two pointsources. In some embodiments, the listening position may be located atany suitable position. For example, the listening position may belocated on a circle centered on the center point of the two pointsources. As another example, the listening position may be on the sameside of the two lines of the two sets of point sources.

It may be understood that the simplified structure of the acousticoutput apparatus shown in FIGS. 10A-10C may be merely by way of example,which may be not a limitation for the present disclosure. In someembodiments, the acoustic output apparatus may include a supportingstructure, a controller, a signal processor, or the like, or anycombination thereof.

FIGS. 11A and 11B are schematic diagrams illustrating an acoustic outputapparatus according to some embodiments of the present disclosure.

In some embodiments, acoustic drivers (e.g., acoustic drivers 1043 or1053) may include multiple narrow-band speakers. As shown in FIG. 11A,the acoustic output apparatus may include a plurality of narrow-bandspeaker units and a signal processing module. On the left or right sideof the user, the acoustic output apparatus may include n groups,narrow-band speaker units, respectively. Each group of narrow-bandspeaker units may have different frequency response curves, and thefrequency response of each group may be complementary and collectivelycover the audible sound frequency band. A narrow-band speaker unit usedherein may be an acoustic driver with a narrower frequency responserange than a low-frequency acoustic driver and/or a high-frequencyacoustic driver. Taking the speaker units located on the left side ofthe user as shown in FIG. 11A as an example: A1˜An and B1˜Bn form ngroups of two point sources. When a same electrical signal is input,each two point sources may generate sounds with different frequencyranges. By setting the distance do of each two point sources, thenear-field and far-field sound of each frequency band may be adjusted.For example, in order to enhance the volume of near-field sound andreduce the volume of far-field leakage, the distance between a pair oftwo point sources corresponding to a high frequency may be less than thedistance between a pair of two point sources corresponding to a lowfrequency.

In some embodiments, the signal processing module may include anEqualizer (EQ) processing module and a Digital Signal Processor (DSP)processing module. The signal processing module may be used to implementsignal equalization and other digital signal processing algorithms (suchas amplitude modulation and phase modulation). The processed signal maybe connected to a corresponding acoustic driver (for example, anarrow-band speaker unit) to output a sound. Preferably, a narrow-bandspeaker unit may be a dynamic coil speaker or a moving iron speaker. Insome embodiments, the narrow-band speaker unit may be a balancedarmature speaker. Two point sources may be constructed using twobalanced armature speakers, and the sound output from the two speakersmay be in opposite phases.

In some embodiments, an acoustic driver (such as acoustic drivers 840,850, 1040 or 1050) may include multiple sets of full-band speakers. Asshown in FIG. 11B, the acoustic output apparatus may include a pluralityof sets of full-band speaker units and a signal processing module. Onthe left or right side of the user, the acoustic output apparatus mayinclude n groups full-band speaker units, respectively. Each full-bandspeaker unit may have the same or similar frequency response curve, andmay cover a wide frequency range.

Taking the speaker units located on the left side of the user as shownin FIG. 11B as an example: A1˜An and B1˜Bn form n groups of two pointsources. The difference between FIGS. 11A and 11B may be that the signalprocessing module in FIG. 11B may include at least one set of filtersfor performing frequency division on the sound source signal to generateelectric signals corresponding to different frequency ranges, and theelectric signals corresponding to different frequency ranges may beinput into each group of full-band speaker units. In this way, eachgroup of speaker units (similar to the two point sources) may producesounds with different frequency ranges separately.

FIGS. 12A-12C are schematic diagrams illustrating an acoustic routeaccording to some embodiments of the present disclosure.

As described above, an acoustic filtering structure may be constructedby setting structures such as a sound tube, a sound cavity, and a soundresistance in an acoustic route to achieve frequency division of sound.FIGS. 12A-12C show schematic structural diagrams of frequency divisionof a sound signal using an acoustic route. It should be noted that FIGS.12A-12C may be examples of setting the acoustic route when using theacoustic route to perform frequency division on the sound signal, andmay not be a limitation on the present disclosure.

As shown in FIG. 12A, an acoustic route may include one or more groupsof lumen structures connected in series, and an acoustic resistancematerial may be provided in the lumen structures to adjust the acousticimpedance of the entire structure to achieve a filtering effect. In someembodiments, a band-pass filtering or a low-pass filtering may beperformed on the sound by adjusting the size of the lumen structuresand/or the acoustic resistance material to achieve frequency division ofthe sound. As shown in FIG. 12B, a structure with one or more sets ofresonant cavities (for example, Helmholtz cavity) may be constructed ona branch of the acoustic route, and the filtering effect may be achievedby adjusting the size of each resonant cavity and the acousticresistance material. As shown in FIG. 12C, a combination of a lumenstructure and a resonant cavity (for example, a Helmholtz cavity) may beconstructed in an acoustic route, and a filtering effect may be achievedby adjusting the size of the lumen structure and/or a resonant cavity,and/or the acoustic resistance material.

FIG. 13 shows a curve of a sound leakage of an acoustic output apparatus(for example, the acoustic output apparatus 800) under the action of twosets of two point sources (a set of high-frequency two point sources anda set of low-frequency two point sources). The frequency division pointsof the two sets of two point sources may be around 700 Hz.

A normalization parameter α may be used to evaluate the volume of theleaked sound (descriptions of a may be found in Equation (4)). As shownin FIG. 13 , compared with a single point source, the two sets of twopoint sources may have a stronger ability to reduce sound leakage. Inaddition, compared with the acoustic output apparatus provided with onlyone set of two point sources, the two sets of two point sources mayoutput high-frequency sounds and low-frequency sounds, separately. Thedistance between the low-frequency two point sources may be greater thanthat of the high-frequency two point sources. In the low-frequencyrange, by setting a larger distance (d1) between the low frequency twopoint sources, the increase in the volume of the near-field sound may begreater than the increase in the volume of the far-field leakage, whichmay achieve a higher volume of the near-field sound output in thelow-frequency band. At the same time, in the low-frequency range,because that the sound leakage of the low frequency two point sources isvery small, increasing the distance d1 may slightly increase the soundleakage. In the high-frequency range, by setting a small distance (d2)between the high frequency two point sources, the problem that thecutoff frequency of high-frequency sound leakage reduction is too lowand the audio band of the sound leakage reduction is too narrow may beovercame. Therefore, by setting the distance d1 and/or the distance d2,the acoustic output apparatus provided in the embodiments of the presentdisclosure may obtain a stronger sound leakage suppressing capabilitythan an acoustic output apparatus having a single point source or asingle set of two point sources.

In some embodiments, affected by factors such as the filtercharacteristic of a circuit, the frequency characteristic of atransducer, and the frequency characteristic of an acoustic route, theactual low-frequency and high-frequency sounds of the acoustic outputapparatus may differ from those shown in FIG. 13 . In addition,low-frequency and high-frequency sounds may have a certain overlap(aliasing) in the frequency band near the frequency division point,causing the total sound leakage reduction of the acoustic outputapparatus not have a mutation at the frequency division point as shownin FIG. 13 . Instead, there may be a gradient and/or a transition in thefrequency band near the frequency division point, as shown by a thinsolid line in FIG. 13 . It may be understood that these differences maynot affect the overall leakage reduction effect of the acoustic outputapparatus provided by the embodiments of the present disclosure.

According to FIGS. 8 to 13 and the related descriptions, the acousticoutput apparatus provided by the present disclosure may be used tooutput sounds in different frequency bands by setting high-frequency twopoint sources and low-frequency two point sources, thereby achieving abetter acoustic output effect. In addition, by setting different sets oftwo point sources with different distances, the acoustic outputapparatus may have a stronger capability to reduce the sound leakage ina high frequency band, and meet the requirements of an open acousticoutput apparatus.

In some alternative embodiments, an acoustic output apparatus mayinclude at least one acoustic driver, and the sound generated by the atleast one acoustic driver may propagate outwards through at least twosound guiding holes coupled with the at least one acoustic driver. Insome embodiments, the acoustic output apparatus may be provided with abaffle structure, so that the at least two sound guiding holes may bedistributed on two sides of the baffle. In some embodiments, the atleast two sound guiding holes may be distributed on both sides of theuser's auricle. At this time, the auricle may serve as a baffle thatseparates the at least two sound guiding holes, so that the at least twosound guiding holes may have different acoustic routes to the user's earcanal. More descriptions of two point sources and a baffle may be foundin International applications No. PCT/CN2019/130921 and No.PCT/CN2019/130942, both filed on Dec. 31, 2019, the entire contents ofeach of which are hereby incorporated by reference in the presentdisclosure.

FIG. 14 is a schematic diagram illustrating another exemplary acousticoutput apparatus 1400 according to some embodiments of the presentdisclosure. As shown in FIG. 14 , the acoustic output apparatus 1400 mayinclude a supporting structure 1410 and an acoustic driver 1420 mountedwithin the supporting structure 1410. In some embodiments, the acousticoutput apparatus 1400 may be worn on the user's body (for example, thehuman body's head, neck, or upper torso) through the supportingstructure 1410. At the same time, the supporting structure 1410 and theacoustic driver 1420 may approach but not block the ear canal, so thatthe user's ear may remain open, thus the user may hear both the soundoutput from the acoustic output apparatus 1400 and the sound of theexternal environment. For example, the acoustic output apparatus 1400may be arranged around or partially around the user's ear, and transmitsounds by means of air conduction or bone conduction.

The supporting structure 1410 may be used to be worn on the user's bodyand include one or more acoustic drivers 1420. In some embodiments, thesupporting structure 1410 may have an enclosed shell structure with ahollow interior, and the one or more acoustic drivers 1420 may belocated inside the supporting structure 1410. In some embodiments, theacoustic output apparatus 1400 may be combined with a product, such asglasses, a headset, a display apparatus, an AR/VR helmet, etc. In thiscase, the supporting structure 1410 may be fixed near the user's ear ina hanging or clamping manner. In some alternative embodiments, a hookmay be provided on the supporting structure 1410, and the shape of thehook may match the shape of the user's auricle, so that the acousticoutput apparatus 1400 may be independently worn on the user's earthrough the hook. The acoustic output apparatus 1400 may communicatewith a signal source (for example, a computer, a mobile phone, or othermobile devices) in a wired or wireless manner (for example, Bluetooth).For example, the acoustic output apparatus 1400 at the left and rightears may be directly in communication connection with the signal sourcein a wireless manner. As another example, the acoustic output apparatus1400 at the left and right ears may include a first output apparatus anda second output apparatus. The first output apparatus may be incommunication connection with the signal source, and the second outputapparatus may be wirelessly connected with the first output apparatus ina wireless manner. The audio output of the first output apparatus andthe second output apparatus may be synchronized through one or moresynchronization signals. A wireless connection disclosed herein mayinclude but not limited to a Bluetooth, a local area network, a widearea network, a wireless personal area network, a near fieldcommunication, or the like, or any combination thereof.

In some embodiments, the supporting structure 1410 may have a shellstructure with a shape suitable for human ears, for example, a circularring, an oval, a polygonal (regular or irregular), a U-shape, a V-shape,a semi-circle, so that the supporting structure 1410 may be directlyhooked at the user's ear. In some embodiments, the supporting structure1410 may include one or more fixed structures. The fixed structure(s)may include an ear hook, a head strip, or an elastic band, so that theacoustic output apparatus 1400 may be better fixed on the user,preventing the acoustic output apparatus 1400 from falling down. Merelyby way of example, the elastic band may be a headband to be worn aroundthe head region. As another example, the elastic band may be a neckbandto be worn around the neck/shoulder region. In some embodiments, theelastic band may be a continuous band and be elastically stretched to beworn on the user's head. In the meanwhile, the elastic band may alsoexert pressure on the user's head so that the acoustic output apparatus1400 may be fixed to a specific position on the user's head. In someembodiments, the elastic band may be a discontinuous band. For example,the elastic band may include a rigid portion and a flexible portion. Therigid portion may be made of a rigid material (for example, plastic ormetal), and the rigid portion may be fixed to the supporting structure1410 of the acoustic output apparatus 1400 by a physical connection. Theflexible portion may be made of an elastic material (for example, cloth,composite, or/and neoprene).

In some embodiments, when the user wears the acoustic output apparatus1400, the supporting structure 1410 may be located above or below theauricle. The supporting structure 1410 may be provided with a soundguiding hole 1411 and a sound guiding hole 1412 for transmitting sound.In some embodiments, the sound guiding hole 1411 and the sound guidinghole 1412 may be located on both sides of the user's auricle,respectively, and the acoustic driver 1420 may output sounds through thesound guiding hole 1411 and the sound guiding hole 1412.

The acoustic driver 1420 may be a component that may receive anelectrical signal, and convert the electrical signal into a sound signalfor output. In some embodiments, in terms of frequency, the type of theacoustic driver 1420 may include a low-frequency acoustic driver, ahigh-frequency acoustic driver, or a full-frequency acoustic driver, orany combination thereof. In some embodiments, the acoustic driver 1420may include a moving coil, a moving iron, a piezoelectric, anelectrostatic, a magnetostrictive driver, or the like, or a combinationthereof.

In some embodiments, the acoustic driver 1420 may include a vibrationdiaphragm. When the vibration diaphragm vibrates, sounds may betransmitted from the front and rear sides of the vibration diaphragm,respectively. In some embodiments, the front side of the vibrationdiaphragm in the supporting structure 1410 may be provided with a frontchamber 1413 for transmitting sound. The front chamber 1413 may beacoustically coupled with the sound guiding hole 1411. The sound on thefront side of the vibration diaphragm may be outputted from the soundguiding hole 1411 through the front chamber 1413. The rear side of thevibration diaphragm in the supporting structure 1410 may be providedwith a rear chamber 1414 for transmitting sound. The rear chamber 1414may be acoustically coupled with the sound guiding hole 1412. The soundon the rear side of the vibration diaphragm may be outputted from thesound guiding hole 1412 through the rear chamber 1414. It should benoted that, when the vibration diaphragm is vibrating, the front sideand the rear side of the vibration diaphragm may simultaneously generatesounds with opposite phases. After passing through the front chamber1413 and rear chamber 1414, respectively, the sounds may propagateoutward from the sound guiding hole 1411 and the sound guiding hole1412, respectively. In some embodiments, by adjusting the structure ofthe front chamber 1413 and the rear chamber 1414, the sounds output bythe acoustic driver 1420 at the sound guiding hole 1411 and the soundguiding hole 1412 may meet specific conditions. For example, bydesigning the lengths of the front chamber 1413 and the rear chamber1414, the sound guiding hole 1411 and the sound guiding hole 1412 mayoutput sounds with a specific phase relationship (for example, oppositephases). Therefore, the problems including a small volume of the soundheard by the user in the near field of the acoustic output apparatus1400 and a large sound leakage in the far field of the acoustic outputapparatus 1400 may be effectively resolved.

In some alternative embodiments, the acoustic driver 1420 may alsoinclude a plurality of vibration diaphragms (e.g., two vibrationdiaphragms). Each of the plurality of vibration diaphragms may vibrateto generate a sound, which may pass through a cavity connected to thevibration diaphragm in the supporting structure, and output fromcorresponding sound guiding hole(s). The plurality of vibrationdiaphragms may be controlled by the same controller or differentcontrollers and generate sounds that satisfy certain phase and amplitudeconditions (for example, sounds of the same amplitude but oppositephases, sounds of different amplitudes and opposite phases, etc.).

As mentioned above, with a certain sound frequency, as the distancebetween two point sources increases, the volume of the sound heard bythe user and the volume of the leaked sound corresponding to the twopoint sources may increase. For a clearer description, the relationshipbetween volume of the sound heard by the user, the volume of soundleakage, and the point source distance d may be further explained inconnection with FIGS. 15 through 17 .

FIG. 15 is a schematic diagram illustrating two point sources and alistening position according to some embodiments of the presentdisclosure. As shown in FIG. 15 , a point source a1 and a point sourcea2 may be on a same side of the listening position. The point source a1may be closer to the listening position, and the point source a1 and thepoint source a2 may output sounds with the same amplitude but oppositephases.

FIG. 16 is a graph illustrating a variation of the volume of the soundheard by the user of two point sources with different distances as afunction of a frequency of sound according to some embodiments of thepresent disclosure. The abscissa may represent the frequency (f) of thesound output by the two point sources (denoted as a1 and a2), and theunit may be hertz (Hz). The ordinate may represent the volume of thesound, and the unit may be decibel (dB). As shown in FIG. 16 , as thedistance between the point source a1 and the point source a2 graduallyincreases (for example, from d to 10d), the sound volume at thelistening position may gradually increase. That is, as the distancebetween the point source a1 and the point source a2 increases, thedifference in sound pressure amplitude (i.e., sound pressure difference)between the two sounds reaching the listening position may becomelarger, making the sound cancellation effect weaker, which may increasethe sound volume at the listening position. However, due to theexistence of sound cancellation, the sound volume at the listeningposition may still be less than the sound volume generated by a singlepoint source at a same position in the low and middle frequency band(for example, a frequency of less than 1000 Hz). However, in thehigh-frequency band (for example, a frequency close to 10000 Hz), due tothe decrease in the wavelength of the sound, mutual enhancement of thesound may appear, making the sound generated by the two point sourceslouder than that of the single point source. In some embodiments, asound pressure may refer to the pressure generated by the sound throughthe vibration of the air.

In some embodiments, by increasing the distance between the two pointsources (for example, the point source a1 and the point source a2), thesound volume at the listening position may be increased. But as thedistance increases, the sound cancellation of the two point sources maybecome weaker, which may lead to an increase of the far-field soundleakage. For illustration purposes, FIG. 17 is a graph illustrating avariation of a normalized parameter of different distances between twopoint sources in the far field along with a frequency of sound accordingto some embodiments of the present disclosure. The abscissa mayrepresent the frequency (f) of the sound, the unit may be Hertz (Hz).The ordinate may use a normalization parameter α for evaluating thevolume of the leaked sound, and the unit may be decibel (dB). As shownin FIG. 17 , taking the normalization parameter α of a single pointsource as a reference, as the distance between the two point sourcesincreases from d to 10d, the normalization parameter α may graduallyincrease, indicating that the sound leakage may gradually increase. Moredescriptions regarding the normalization parameter α may be found inequation (4) and related descriptions.

In some embodiments, adding a baffle structure to the acoustic outputapparatus may be beneficial to improve the output effect of the acousticoutput apparatus, that is, to increase the sound intensity at thenear-field listening position, while reduce the volume of the far-fieldsound leakage. For illustration, FIG. 18 is a diagram illustrating anexemplary baffle provided between two point sources according to someembodiments of the present disclosure. As shown in FIG. 18 , when abaffle is provided between the point source a1 and the point source a2,in the near field, the sound wave of the point source a2 may need tobypass the baffle to interfere with the sound wave of the point sourcea1 at the listening position, which may be equivalent to increasing thelength of the acoustic route from the point source a2 to the listeningposition. Therefore, assuming that the point source a1 and the pointsource a2 have a same amplitude, compared to the case without a baffle,the difference in the amplitude of the sound waves of the point sourcea1 and the point source a2 at the listening position may increase, sothat the degree of cancellation of the two sounds at the listeningposition may decrease, causing the sound volume at the listeningposition to increase. In the far field, because the sound wavesgenerated by the point source a1 and the point source a2 do not need tobypass the baffle in a large space, the sound waves may interfere(similar to the case without a baffle). Compared to the case without abaffle, the sound leakage in the far field may not increasesignificantly. Therefore, a baffle structure being provided between thepoint source a1 and the point source a2 may increase the sound volume atthe near-field listening position significantly while the volume of thefar-field leakage does not increase significantly.

In the present disclosure, when the two point sources are located onboth sides of the auricle, the auricle may serve as a baffle, so theauricle may also be referred to as a baffle for convenience. As anexample, due to the existence of the auricle, the result may beequivalent to that the near-field sound may be generated by two pointsources with a distance of D1 (also known as mode 1). The far-fieldsound may be generated by two point sources with a distance of D2 (alsoknown as mode 2), and D1>D2. FIG. 19 is a graph illustrating a variationof the volume of a sound heard by a user as a function of the frequencyof sound when the auricle is located between two point sources accordingto some embodiments of the present disclosure. As shown in FIG. 19 ,when the frequency is low (for example, when the frequency is less than1000 Hz), the volume at the near-field sound (that is, the sound heardby the user by the user's ear) may basically be the same as that of thenear-field sound in mode 1, be greater than the volume of the near-fieldsound in mode 2, and be close to the volume of the near-field sound of asingle point source. As the frequency increases (for example, when thefrequency is between 2000 Hz and 7000 Hz), the volume of the near-fieldsound in mode 1 and the two point sources being distributed on bothsides of the auricle may be greater than that of the one point source.It shows that when the user's auricle is located between the two pointsources, the volume of the near-field sound transmitted from the soundsource to the user's ear may be effectively enhanced. FIG. 20 is a graphillustrating a variation of the volume of a leaked sound as a functionof the frequency of sound when the auricle is located between two pointsources according to some embodiments of the present disclosure. Asshown in FIG. 20 , as the frequency increases, the volume of thefar-field leakage may increase. When the two point sources aredistributed on both sides of the auricle, the volume of the far-fieldleakage generated by the two point sources may be basically the same asthe volume of the far-field leakage in mode 2, and both of which may beless than the volume of the far-field leakage in mode 1 and the volumeof the far-field leakage of a single point source. It shows that whenthe user's auricle is located between the two point sources, the soundtransmitted from the sound source to the far field may be effectivelyreduced, that is, the sound leakage from the sound source to thesurrounding environment may be effectively reduced. FIG. 21 is a graphillustrating a variation of a normalized parameter as a function of thefrequency of sound when two point sources of an acoustic outputapparatus is distributed on both sides of the auricle according to someembodiments of the present disclosure. As shown in FIG. 21 , when thefrequency is less than 10000 Hz, the normalized parameter of the twopoint sources being distributed on both sides of the auricle may be lessthan the normalized parameter in the case of mode 1 (no baffle structurebetween the two point sources, and the distance is D1), mode 2 (nobaffle structure between the two point sources, and the distance is D2),and the single point source, which may show that when the two pointsources are located on both sides of the auricle, the acoustic outputapparatus may have a better capability to reduce the sound leakage.

In order to further explain the effect of the acoustic output apparatuswith or without a baffle between the two point sources or two soundguiding holes, the volume of the near-field sound at the listeningposition and/or volume of the far-field leakage under differentconditions may specifically be described below.

FIG. 22 is a graph illustrating a variation of the volume of a soundheard by the user and volume of a leaked sound as a function of thefrequency of sound with and without a baffle between two point sourcesaccording to some embodiments of the present disclosure. As shown inFIG. 22 , after adding a baffle between the two point sources (i.e., twosound guiding holes) of the acoustic output apparatus, in the nearfield, it may be equivalent to increasing the distance between the twopoint sources, and the sound volume at the near-field listening positionmay be equivalent to being generated by a set of two point sources witha large distance. The volume of the near-field sound may besignificantly increased compared to the case without a baffle. In thefar field, because the interference of the sound waves generated by thetwo point sources may be rarely affected by the baffle, the soundleakage may be equivalent to being generated by two point sources with asmall distance, therefore the sound leakage may not change significantlywith or without the baffle. It may be seen that by setting a bafflebetween two sound guiding holes (i.e., two point sources), the abilityof the sound output apparatus to reduce the sound leakage may beeffectively improved, and the volume of the near-field sound of theacoustic output apparatus may be increased significantly. Therefore, therequirements for sound production components of the acoustic outputapparatus may be reduced. At the same time, the simple circuit structuremay reduce the electrical loss of the acoustic output apparatus, so thatthe working time of the acoustic output apparatus may be greatlyprolonged under a certain amount of electricity.

FIG. 23 is a graph illustrating a variation of the volume of a soundheard by the user and the volume of a leaked sound as a function of thedistance between two point sources when the frequency of the two pointsources is 300 Hz according to some embodiments of the presentdisclosure. FIG. 24 is a graph illustrating a variation of the volume ofa sound heard by the user and the volume of a leaked sound as a functionof the distance between two point sources when the frequency of the twopoint sources is 1000 Hz according to some embodiments of the presentdisclosure. As shown in FIGS. 23 and 24 , in the near field, when thefrequency is 300 Hz or 1000 Hz, as the increase of the distanced of thetwo point sources, the volume of the sound heard by the user with abaffle between the two point sources may be greater than that without abaffle between the two point sources, which shows that at thisfrequency, the baffle structure between the two point sources mayeffectively increase the volume of the sound heard by the user in thenear field. In the far field, the volume of the leaked sound with abaffle between the two point sources may be equivalent to that without abaffle between the two point sources, which shows that at thisfrequency, with or without a baffle structure arranged between the twopoint sources has little effect on the far-field sound leakage.

FIG. 25 is a graph illustrating a variation of the volume of a soundheard by the user and the volume of a leaked sound as a function of thedistance when the frequency of the two point sources is 5000 Hzaccording to some embodiments of the present disclosure. As shown inFIG. 25 , in the near field, when the frequency is 5000 Hz, as thedistanced of the two point sources increases, the volume of the soundheard by the user when there is a baffle between the two point sourcesmay be greater than that when there is no baffle. In the far-field, thevolume of the leaked sound of the two point sources with and withoutbaffle may be fluctuant as a function of the distanced. Overall, whetherthe baffle structure is arranged between the two point sources haslittle effect on the far-field leakage.

FIGS. 26-28 are graphs illustrating a variation of the volume of a soundheard by the user as a function of the frequency of sound when thedistanced of two point sources is 1 cm, 2 cm, 3 cm, respectively,according to some embodiments of the present disclosure. FIG. 29 is agraph illustrating a variation of a normalized parameter of a far fieldas a function of the frequency of sound when the distance d of two pointsources is 1 cm according to some embodiments of the present disclosure.FIG. 30 is a graph illustrating a variation of a normalized parameter ofa far field as a function of the frequency of sound when the distance dof two point sources is 2 cm according to some embodiments of thepresent disclosure. FIG. 31 is a graph illustrating a variation of anormalized parameter of a far field as a function of the frequency ofsound when the distanced of two point sources is 4 cm according to someembodiments of the present disclosure. As shown in FIGS. 26 through 28 ,for the different distances d of the sound guiding holes (for example, 1cm, 2 cm, 4 cm), at a certain frequency, in the near-field listeningposition (for example, the user's ear), the sound volume of two soundguiding holes located on both sides of the auricle (i.e., the “baffleeffect” situation shown in the figure) may be greater than the soundvolume of two sound guiding holes located on a same side of the auricle(i.e., the case of “without baffle” as shown in the figures). Thecertain frequency may be below 10000 Hz, below 5000 Hz, or below 1000Hz.

As shown in FIGS. 29 to 31 , for the different distances d of the soundguiding holes (for example, 1 cm, 2 cm, and 4 cm), at a certainfrequency, in the far-field position (for example, the environmentposition away from the user's ear), the volume of the leaked soundgenerated when the two sound guiding holes are provided on both sides ofthe auricle may be smaller than that generated when the two soundguiding holes are not provided on both sides of the auricle. It shouldbe noted that as the distance between two sound guiding holes or twopoint sources increases, the interference cancellation of sound at thefar-field position may weaken, leading to a gradual increase in thefar-field leakage and a weaker ability to reduce sound leakage.Therefore, the distance d between two sound guiding holes or the twopoint sources may not be too large. In some embodiments, in order tokeep the output sound as loud as possible in the near field, andsuppress the sound leakage in the far field, the distance d between thetwo sound guiding holes may be set to be no more than, for example, 20cm, 12 cm, 10 cm, 6 cm, or the like. In some embodiments, consideringthe size of the acoustic output apparatus and the structuralrequirements of the sound guiding holes, the distance d between the twosound guiding holes may be set to be in a range of, for example, 1 cm to12 cm, 1 cm to 10 cm, 1 cm to 8 cm, 1 cm to 6 cm, 1 cm to 3 cm, or thelike.

It should be noted that the above description is merely for theconvenience of description, and not intended to limit the scope of thepresent disclosure. It may be understood that, for those skilled in theart, after understanding the principle of the present disclosure,various modifications and changes in the forms and details of theacoustic output apparatus may be made without departing from thisprinciple. For example, in some embodiments, a plurality of soundguiding holes may be set on both sides of the baffle. The number of thesound guiding holes on both sides of the baffle may be the same ordifferent. For example, the number of sound guiding holes on one side ofthe baffle may be two, and the number of sound guiding holes on theother side may be two or three. These modifications and changes maystill be within the protection scope of the present disclosure.

In some embodiments, on the premise of maintaining the distance betweenthe two point sources, a relative position of the listening position tothe two point sources may have a certain effect on the volume of thenear-field sound and the far-field leakage reduction. In order toimprove the acoustic output effect of the acoustic output apparatus, insome embodiments, the acoustic output apparatus may be provided with atleast two sound guiding holes. The at least two sound guiding holes mayinclude two sound guiding holes located on the front and back sides ofthe user's auricle, respectively. In some embodiments, considering thatthe sound propagated from the sound guiding hole located on the rearside of the user's auricle needs to bypass over the auricle to reach theuser's ear canal, the acoustic route between the sound guiding holelocated on the front side of the auricle and the user's ear canal (i.e.,the acoustic distance from the sound guiding hole to the user's earcanal entrance) is shorter than the acoustic route between the soundguiding hole located on the rear side of the auricle and the user's ear.In order to further explain the effect of the listening position on theacoustic output effect, four representative listening positions(listening position 1, listening position 2, listening position 3,listening position 4) may be selected as shown in FIG. 32 . Thelistening position 1, the listening position 2, and the listeningposition 3 may have equal distance from the point source a1, which maybe r1. The distance between the listening position 4 and the pointsource a1 may be r2, and r2<r1. The point source a1 and the point sourcea2 may generate sounds with opposite phases, respectively.

FIG. 33 is a graph illustrating the volume of a sound heard by a user oftwo point sources without baffle at different listening positions as afunction of the frequency of sound according to some embodiments of thepresent disclosure. FIG. 34 is a graph illustrating a normalizedparameter of different listening positions as a function of thefrequency of sound. The normalized parameter may be obtained withreference to Equation (4). As shown in FIGS. 33 and 34 , for thelistening position 1, since the difference between the acoustic routesfrom the point source a1 and the point source a2 to the listeningposition 1 is small, the difference in amplitude of the sounds producedby the two point sources at the listening position 1 may be small.Therefore, an interference of the sounds of the two point sources at thelistening position 1 may cause the volume of the sound heard by the userto be smaller than that of other listening positions. For the listeningposition 2, compared with the listening position 1, the distance betweenthe listening position 2 and the point source a1 may remain unchanged,that is, the acoustic route from the point source a1 to the listeningposition 2 may not change. However, the distance between the listeningposition 2 and the point source a2 may be longer, and the length of theacoustic route between the point source a2 and the listening position 2may increase. The amplitude difference between the sound generated bythe point source a1 and the sound generated by the point source a2 atthe listening position 2 may increase. Therefore, the volume of thesound transmitted from the two point sources after interference at thelistening position 2 may be greater than that at the listening position1. Among all positions on an arc with a radius of r1, a differencebetween the acoustic route from the point source a1 to the listeningposition 3 and the acoustic route from the point source a2 to thelistening position 3 may be the longest. Therefore, compared with thelistening position 1 and the listening position 2, the listeningposition 3 may have the highest volume of the sound heard by the user.For the listening position 4, the distance between the listeningposition 4 and the point source a1 may be short. The sound amplitude ofthe point source a1 at the listening position 4 may be large. Therefore,the volume of the sound heard by the user at the listening position 4may be large. In summary, the volume of the sound heard by the user atthe near-field listening position may change as the listening positionand the relative position of the two point sources change. When thelistening position is on the line between the two point sources and onthe same side of the two point sources (for example, listening position3), the acoustic route difference between the two point sources at thelistening position may be the largest (the acoustic route difference maybe the distance d between the two point sources). In this case (i.e.,when the auricle is not used as a baffle), the volume of the sound heardby the user at this listening position may be greater than that at otherlocations. According to Equation (4), when the far-field leakage isconstant, the normalization parameter corresponding to this listeningposition may be the smallest, and the leakage reduction capability maybe the strongest. At the same time, reducing the distance r1 between thelistening position (for example, listening position 4) and the pointsource a1 may further increase the volume at the listening position, atthe same time reduce the sound leakage, and improve the capability toreduce leakage.

FIG. 35 is a graph illustrating the volume of the sound heard by theuser of two point sources with baffle (as shown in FIG. 32 ) atdifferent listening positions in the near field as a function offrequency according to some embodiments of the present disclosure. FIG.36 is a graph of the normalization parameters of different listeningpositions obtained with reference to Equation (4) based on FIG. 35 , asa function of frequency. As shown in FIGS. 35 and 36 , compared to thecase without a baffle, the volume of the sound heard by the usergenerated by the two point sources at listening position 1 may increasesignificantly when there is a baffle. The volume of the sound heard bythe user at the listening position 1 may exceed that at the listeningposition 2 and the listening position 3. The reason may be that theacoustic route from the point source a2 to the listening position 1 mayincrease after a baffle is set between the two point sources. As aresult, the acoustic route difference between the two point sources atthe listening position 1 may increase significantly. The amplitudedifference between the sounds generated by the two point sources at thelistening position 1 may increase, making it difficult to produce soundinterference cancellation, thereby increasing the volume of the soundheard by the user generated at the listening position 1 significantly.At the listening position 4, since the distance between the listeningposition and the point source a1 is further reduced, the sound amplitudeof the point source a1 at this position may be larger. The volume of thesound heard by the user at the listening position 4 may still be thelargest among the four listening positions. For listening position 2 andlistening position 3, since the effect of the baffle on the acousticroute from the point source a2 to the two listening positions is notvery obvious, the volume increase effect at the listening position 2 andthe listening position 3 may be less than that at the listening position1 and the listening position 4 which are closer to the baffle.

The volume of the leaked sound in the far field may not change withlistening positions, and the volume of the sound heard by the user atthe listening position in the near field may change with listeningpositions. In this case, according to Equation (4), the normalizationparameter of the acoustic output apparatus may vary in differentlistening positions. Specifically, a listening position with a largevolume of sound heard by the user (e.g., listening position 1 andlistening position 4) may have a small normalization parameter andstrong capability to reduce sound leakage. A listening position with alow volume of sound heard by the user (e.g., listening position 2 andlistening position 3) may have a large normalization parameter and weakcapability to reduce leakage.

Therefore, according to the actual application scenario of the acousticoutput apparatus, the user's auricle may serve as a baffle. In thiscase, the two sound guiding holes on the acoustic output apparatus maybe arranged on the front side and the back side of the auricle,respectively, and the ear canal may be located between the two soundguiding holes as a listening position. In some embodiments, by designingthe positions of the two sound guiding holes on the acoustic outputapparatus, the distance between the sound guiding hole on the front sideof the auricle and the ear canal may be smaller than the distancebetween the sound guiding hole on the back side of the auricle and theear canal. In this case, the acoustic output apparatus may produce alarge sound amplitude at the ear canal since the sound guiding hole onthe front side of the auricle is close to the ear canal. The soundamplitude formed by the sound guiding hole on the back of the auriclemay be smaller at the ear canal, which may avoid the interferencecancellation of the sound at the two sound guiding holes at the earcanal, thereby ensuring that the volume of the sound heard by the userat the ear canal is large. In some embodiments, the acoustic outputapparatus may include one or more contact points (e.g., “an inflectionpoint” on a supporting structure to match the shape of the ear) that cancontact with the auricle when it is worn. The contact point(s) may belocated on a line connecting the two sound guiding holes or on one sideof the line connecting the two sound guiding holes. And a ratio of thedistance between the front sound guiding hole and the contact point(s)to the distance between the rear sound guiding hole and the contactpoint(s) may be 0.05-20. In some embodiments, the ratio may be 0.1-10.In some embodiments, the ratio may be 0.2-5. In some embodiments, theratio may be 0.4-2.5.

FIG. 37 is a schematic diagram illustrating two point sources and abaffle (e.g., an auricle) according to some embodiments of the presentdisclosure. In some embodiments, a position of the baffle between thetwo sound guiding holes may have a certain influence on the acousticoutput effect. Merely by way of example, as shown in FIG. 37 , a bafflemay be provided between a point source a1 and a point source a2, alistening position may be located on the line connecting the pointsource a1 and the point source a2. In addition, the listening positionmay be located between the point source a1 and the baffle. A distancebetween the point source a1 and the baffle may be L. A distance betweenthe point source a1 and the point source a2 may be d. A distance betweenthe point source a1 and the sound heard by the user may be L1. Adistance between the listening position and the baffle may be L2. Whenthe distance L1 is constant, a movement of the baffle may causedifferent ratios of L to d, thereby obtaining different volumes of thesound heard by the user at the listening position and/or the volumes ofthe far-field leakage.

FIG. 38 is a graph illustrating a variation of the volume of anear-field sound as a function of the frequency of sound when a baffleis at different positions according to some embodiments of the presentdisclosure. FIG. 39 is a graph illustrating a variation of the volume ofa far-field leakage as a function of the frequency of sound when abaffle is at different positions according to some embodiments of thepresent disclosure. FIG. 40 is a graph illustrating a variation of anormalization parameter as a function of the frequency of sound when abaffle is at different positions according to some embodiments of thepresent disclosure. According to FIGS. 38-40 , the volume of thefar-field leakage may vary little with the change of the position of thebaffle between the two point sources. In a situation that the distance dbetween the point source a1 and the point source a2 remains constant,when L decreases, the volume at the listening position may increase, thenormalization parameter may decrease, and the capability to reduce soundleakage may be enhanced. In the same situation, when L increases, thevolume at the listening position may increase, the normalizationparameter may increase, and the capability to reduce sound leakage maybe weakened. A reason for the above result may be that when L is small,the listening position may be close to the baffle, an acoustic route ofthe sound wave from the point source a2 to the listening position may beincreased due to the baffle. In this case, an acoustic route differencebetween the point source a1 and the point source a2 to the listeningposition may be increased and the interference cancellation of the soundmay be reduced. As a result, the volume at the listening position may beincreased after the baffle is added. When L is large, the listeningposition may be far away from the baffle. The baffle may have a smalleffect on the acoustic route difference between the point source a1 andthe point source a2 to the listening position. As a result, a volumechange at the listening position may be small after the baffle is added.

As described above, by designing positions of the sound guiding holes onthe acoustic output apparatus, an auricle of a human body may serve as abaffle to separate different sound guiding holes when the user wears theacoustic output apparatus. In this case, a structure of the acousticoutput apparatus may be simplified, and the output effect of theacoustic output apparatus may be further improved. In some embodiments,the positions of the two sound guiding holes may be properly designed sothat a ratio of a distance between the sound guiding hole on the frontside of the auricle and the auricle (or a contact point on the acousticoutput apparatus for contact with the auricle) to a distance between thetwo sound guiding holes may be less than or equal to 0.5 when the userwears the acoustic output apparatus. In some embodiments, the ratio maybe less than or equal to 0.3. In some embodiments, the ratio may be lessthan or equal to 0.1. In some embodiments, the ratio of the distancebetween the sound guiding hole on the front side of the auricle and theauricle (or a contact point on the acoustic output apparatus for contactwith the auricle) to the distance between the two sound guiding holesmay be larger than or equal to 0.05. In some embodiments, a second ratioof the distance between the two sound guiding holes to a height of theauricle may be larger than or equal to 0.2. In some embodiments, thesecond ratio may be less than or equal to 4. In some embodiments, theheight of the auricle may refer to a length of the auricle in adirection perpendicular to a sagittal plane.

It should be noted that an acoustic route from an acoustic driver to asound guiding hole in the acoustic output apparatus may have a certaineffect on the volumes of the near-field sound and far-field soundleakage. The acoustic route may be changed by adjusting a cavity lengthbetween a vibration diaphragm in the acoustic output apparatus and thesound guiding hole. In some embodiments, the acoustic driver may includea vibration diaphragm. The front and rear sides of the vibrationdiaphragm may be coupled to two sound guiding holes through a frontchamber and a rear chamber, respectively. The acoustic routes from thevibration diaphragm to the two sound guiding holes may be different. Insome embodiments, a ratio of the lengths of the acoustic routes betweenthe vibration diaphragm and the two sound guiding holes may be, forexample, 0.5-2, 0.6-1.5, or 0.8-1.2.

In some embodiments, on the premise of keeping the phases of the soundsgenerated at the two sound guiding holes opposite, the amplitudes of thesounds generated at the two sound guiding holes may be changed toimprove the output effect of the acoustic output apparatus.Specifically, impedances of acoustic routes connecting the acousticdriver and the two sound guiding holes may be adjusted so as to adjustthe sound amplitude at each of the two sound guiding holes. In someembodiments, the impedance may refer to a resistance that a medium needsto overcome during displacement when acoustic waves are transmitted. Theacoustic routes may or may not be filled with a damping material (e.g.,a tuning net, a tuning cotton, etc.) so as to adjust the soundamplitude. For example, a resonance cavity, a sound hole, a sound slit,a tuning net, and/or a tuning cotton may be disposed in an acousticroute so as to adjust the acoustic resistance, thereby changing theimpedances of the acoustic route. As another example, an aperture ofeach of the two sound guiding holes may be adjusted to change theacoustic resistance of the acoustic routes corresponding to the twosound guiding holes. In some embodiments, a ratio of the acousticimpedance of the acoustic route between the acoustic driver (thevibration diaphragm) and one of the two sound guiding holes to theacoustic route between the acoustic driver and the other sound guidinghole may be 0.5-2 or 0.8-1.2.

It should be noted that the above descriptions are merely forillustration purposes, and not intended to limit the present disclosure.It should be understood that, for those skilled in the art, afterunderstanding the principle of the present disclosure, variousmodifications and changes may be made in the forms and details of theacoustic output apparatus without departing from this principle. Forexample, the listening position may not be on the line connecting thetwo point sources, but may also be above, below, or in an extensiondirection of the line connecting the two point sources. As anotherexample, a measurement method of the distance from a point sound sourceto the auricle, and a measurement method of the height of the auriclemay also be adjusted according to different scenarios. These similarchanges may be all within the protection scope of the presentdisclosure.

FIG. 41 is a schematic diagram illustrating another exemplary acousticoutput apparatus according to some embodiments of the presentdisclosure.

For human ears, the frequency band of sound that can be heard may beconcentrated in a mid-low-frequency band. An optimization goal in themid-low-frequency band may be to increase a volume of the sound heard bythe user. If the listening position is fixed, parameters of the twopoint sources may be adjusted such that the volume of the sound heard bythe user may increase significantly while a volume of leaked sound maybe substantially unchanged (an increase in the volume of the sound heardby the user may be greater than an increase in the volume of the soundleakage). In a high-frequency band, a sound leakage reduction effect ofthe two point sources may be weaker. In the high-frequency band, anoptimization goal may be reducing a sound leakage. The sound leakage maybe further reduced by adjusting the parameters of the two point sourcesof different frequencies. In some embodiments, the acoustic outputapparatus 1400 may also include an acoustic driver 1430. The acousticdriver 1430 may output sounds from two of second sound guiding holes.Details regarding the acoustic driver 1430, the second sound guidingholes, and a structure therebetween may be described with reference tothe acoustic driver 1420 and the first sound guiding holes. In someembodiments, the acoustic driver 1430 and the acoustic driver 1420 mayoutput sounds of different frequencies. In some embodiments, theacoustic output apparatus may further include a controller configured tocause the acoustic driver 1420 to output sound in the first frequencyrange, and cause the acoustic driver 1430 to output sound in the secondfrequency range. The second frequency range may include frequencieshigher than the first frequency range. For example, the first frequencyrange may be 100 Hz-1000 Hz, and the second frequency range may be 1000Hz-10000 Hz.

In some embodiments, the acoustic driver 1420 may be a low-frequencyspeaker, and the acoustic driver 1430 may be a mid-high-frequencyspeaker. Due to different frequency response characteristics of thelow-frequency speaker and the mid-high-frequency speaker, frequencybands of the output sound may also be different. High-frequency bandsand low-frequency bands may be divided by using the low-frequencyspeakers and the mid-high-frequency speakers, and accordingly, twolow-frequency point sources and two mid-high-frequency point sources maybe constructed to perform near-field sound output and a far-fieldleakage reduction. For example, the acoustic driver 1420 may provide twopoint sources for outputting low-frequency sound through the soundguiding hole 1411 and the sound guiding hole 1412, which may be mainlyused for outputting sound in low-frequency band. The two low-frequencypoint sources may be distributed on both sides of an auricle to increasea volume near the near-field ear. The acoustic driver 1430 may providetwo point sources for outputting mid-high-frequency sound through twosecond sound guiding holes. A mid-high-frequency sound leakage may bereduced by adjusting a distance between the two second sound guidingholes. The two mid-high-frequency point sources may be distributed onboth sides of the auricle or on the same side of the auricle.Alternatively, the acoustic driver 1420 may provide two point sourcesfor outputting full-frequency sound through the sound guiding hole 1411and the sound guiding hole 1412 so as to further increase the volume ofthe near-field sound.

Further, the distance d2 between the two second sound guiding holes maybe less than the distance d1 between the sound guiding hole 1411 and thesound guiding hole 1412, that is, d1 may be larger than d2. Forillustration purpose, as shown in FIG. 13 , it may be possible to obtaina stronger sound leakage reduction capability than a single point sourceand one set of two point sources by setting two sets of two pointsources including one set of two low-frequency point sources and one setof two high-frequency point sources with different distances.

It should be noted that the positions of the sound guiding holes of theacoustic output apparatus may be not limited to the case that the twosound guiding holes 1411 and 1412 corresponding to the acoustic driver1420 shown in FIG. 41 are distributed on both sides of the auricle, andthe case that the two sound guiding holes corresponding to the acousticdriver 1430 are distributed on the front side of the auricle. Forexample, in some embodiments, two second sound guiding holescorresponding to the acoustic driver 1430 may be distributed on the sameside of the auricle (e.g., a rear side, an upper side, or a lower sideof the auricle). As another example, in some embodiments, the two secondsound guiding holes corresponding to the acoustic driver 1430 may bedistributed on both sides of the auricle. In some embodiments, when thesound guiding holes 1411 and the sound guiding hole 1412 (and/or the twosecond sound guiding holes) are located on the same side of the auricle,a baffle may be disposed between the sound guiding holes 1411 and thesound guiding hole 1412 (and/or the two second sound guiding holes) soas to further increase the volume of the near-field sound and reduce thefar-field sound leakage. For a further example, in some embodiments, thetwo sound guiding holes corresponding to the acoustic driver 1420 mayalso be located on the same side of the auricle (e.g., a front side, arear side, an upper side, or a lower side of the auricle).

In practical applications, the acoustic output apparatus may includedifferent application forms such as bracelets, glasses, helmets,watches, clothings, or backpacks, smart headsets, etc. In someembodiments, an augmented reality technology and/or a virtual realitytechnology may be applied in the acoustic output apparatus so as toenhance a user's audio experience. For illustration purposes, a pair ofglasses with a sound output function may be provided as an example.Exemplary glasses may be or include augmented reality (AR) glasses,virtual reality (VR) glasses, etc.

FIG. 42 is a schematic diagram illustrating a longitudinal sectionalview of an exemplary acoustic output apparatus 4200 according to someembodiments of the present disclosure. It should be noted that, withoutdeparting from the spirit and scope of the present disclosure, thecontents described below may be applied to an air conduction acousticoutput apparatus and a bone conduction acoustic output apparatus.

As shown in FIG. 42 , in some embodiments, the acoustic output apparatus4200 may include a first magnetic component 4202, a first magneticconductive component 4204, a second magnetic conductive component 4206,a second magnetic component 4208, a vibration plate 4205, and a voicecoil 4238. One or more of the components of acoustic output apparatus4200 may form a magnetic system. For example, the magnetic system mayinclude the first magnetic component 4202, the first magnetic conductivecomponent 4204, the second magnetic conductive component 4206, and thesecond magnetic component 4208. The magnetic system may generate a firsttotal magnetic field (or referred to as a total magnetic field of themagnetic system or a first magnetic field). The first total magneticfield may be formed by all magnetic fields generated by all componentsof the magnetic system (e.g., the first magnetic component 4202, thefirst magnetic conductive component 4204, the second magnetic conductivecomponent 4206, and the second magnetic component 4208).

A magnetic component used herein refers to any component that maygenerate a magnetic field, such as a magnet. In some embodiments, amagnetic component may have a magnetization direction, which refers tothe direction of a magnetic field inside the magnetic component. In someembodiments, the first magnetic component 4202 may include a firstmagnet, which may generate a second magnetic field, and the secondmagnetic component 4208 may include a second magnet. The first magnetand the second magnet may be of the same type or different types. Insome embodiments, a magnet may include a metal alloy magnet, a ferrite,or the like. The metal alloy magnet may include neodymium iron boron,samarium cobalt, aluminum nickel cobalt, iron chromium cobalt, aluminumiron boron, iron carbon aluminum, or the like, or any combinationthereof. The ferrite may include barium ferrite, steel ferrite,ferromanganese ferrite, lithium manganese ferrite, or the like, or anycombination thereof.

A magnetic conductive component may also be referred to as a magneticfield concentrator or an iron core. The magnetic conductive componentmay be used to form a magnetic field loop. The magnetic conductivecomponent may adjust the distribution of a magnetic field (e.g., thesecond magnetic field generated by the first magnetic component 4202).In some embodiments, the magnetic conductive component may include asoft magnetic material. Exemplary soft magnetic materials may include ametal material, a metal alloy material, a metal oxide material, anamorphous metal material, or the like. For example, the soft magneticmaterial may include iron, iron-silicon based alloy, iron-aluminum basedalloy, nickel-iron based alloy, iron-cobalt based alloy, low carbonsteel, silicon steel sheet, silicon steel sheet, ferrite, or the like.In some embodiments, the magnetic conductive component may bemanufactured by, for example, casting, plastic processing, cuttingprocessing, powder metallurgy, or the like, or any combination thereof.The casting may include sand casting, investment casting, pressurecasting, centrifugal casting, or the like. The plastic processing mayinclude rolling, casting, forging, stamping, extrusion, drawing, or thelike, or any combination thereof. The cutting processing may includeturning, milling, planning, grinding, or the like. In some embodiments,the magnetic conductive component may be manufactured by a 3D printingtechnique, a computer numerical control machine tool, or the like.

In some embodiments, one or more of the first magnetic component 4202,the first magnetic conductive component 4204, and the second magneticconductive component 4206 may have an axisymmetric structure. Theaxisymmetric structure may include a ring structure, a columnarstructure, or other axisymmetric structures. For example, the structureof the first magnetic component 4202 and/or the first magneticconductive component 4204 may be a cylinder, a rectangularparallelepiped, or a hollow ring (e.g., a cross-section of the hollowring may be the shape of a racetrack). As another example, the structureof the first magnetic component 4202 and the structure of the firstmagnetic conductive component 4204 may be coaxial cylinders having thesame diameter or different diameters. In some embodiments, the secondmagnetic conductive component 4206 may have a groove-shaped structure.The groove-shaped structure may include a U-shaped cross section (asshown in FIG. 42 ). The groove-shaped second magnetic conductivecomponent 4206 may include a bottom plate and a side wall. In someembodiments, the bottom plate and the side wall may form an integralassembly. For example, the side wall may be formed by extending thebottom plate in a direction perpendicular to the bottom plate. In someembodiments, the bottom plate may be mechanically connected to the sidewall. As used herein, a mechanical connection between two components mayinclude a bonded connection, a locking connection, a welded connection,a rivet connection, a bolted connection, or the like, or any combinationthereof.

The second magnetic component 4208 may have a shape of a ring or asheet. For example, the second magnetic component 4208 may have a ringshape. The second magnetic component 4208 may include an inner ring andan outer ring. In some embodiments, the shape of the inner ring and/orthe outer ring may be a circle, an ellipse, a triangle, a quadrangle, orany other polygon. In some embodiments, the second magnetic component4208 may include a plurality of magnets. Two ends of a magnet of theplurality of magnets may be mechanically connected to or have a certaindistance from the ends of an adjacent magnet. The distance between theadjacent magnets may be the same or different. For example, the secondmagnetic component 4208 may include two or three sheet-like magnetswhich are arranged equidistantly. The shape of a sheet-like magnet maybe a fan shape, a quadrangular shape, or the like. In some embodiments,the second magnetic component 4208 may be coaxial with the firstmagnetic component 4202 and/or the first magnetic conductive component4204.

In some embodiments, an upper surface of the first magnetic component4202 may be mechanically connected to a lower surface of the firstmagnetic conductive component 4204 as shown in FIG. 42 . A lower surfaceof the first magnetic component 4202 may be mechanically connected tothe bottom plate of the second magnetic conductive component 4206. Alower surface of the second magnetic component 4208 may be mechanicallyconnected to the side wall of the second magnetic conductive component4206.

In some embodiments, a magnetic gap may be formed between the firstmagnetic component 4202 (and/or the first magnetic conductive component4204) and the inner ring of the second magnetic component 4208 (and/orthe second magnetic conductive component 4206). The voice coil 4238 maybe disposed in the magnetic gap and mechanically connected to thevibration plate 4205. A voice coil refers to an element that maytransmit an audio signal. The voice coil 4238 may be located in amagnetic field formed by the first magnetic component 4202, the firstmagnetic conductive component 4204, the second magnetic conductivecomponent 4206, and the second magnetic component 4208. When a currentis applied to the voice coil 4238, the ampere force generated by themagnetic field may drive the voice coil 4238 to vibrate. The vibrationof the voice coil 4238 may drive the vibration plate 4205 to vibrate togenerate sound waves, which may be transmitted to a user's ears via airconduction and/or the bone conduction. In some embodiments, the distancebetween the bottom of the voice coil 4238 and the second magneticconductive component 4206 may be equal to that between the bottom of thesecond magnetic component 4208 and the second magnetic conductivecomponent 4206.

In some embodiments, for a speaker device having a single magneticcomponent, the magnetic induction lines passing through the voice coil4238 may be uneven and divergent. A magnetic leakage may be formed inthe magnetic system, that is, some magnetic induction lines may leakoutside the magnetic gap and fail to pass through the voice coil 4238.This may result in a decrease in a magnetic induction intensity (or amagnetic field intensity) at the voice coil 4238, and affect thesensitivity of the acoustic output apparatus 4200. To eliminate orreduce the magnetic leakage, the acoustic output apparatus 4200 mayfurther include at least one second magnetic component and/or at leastone third magnetic conductive component (not shown in the figure). Theat least one second magnetic component and/or at least one thirdmagnetic conductive component may suppress the magnetic leakage andrestrict the shape of the magnetic induction lines passing through thevoice coil 4238, so that more magnetic induction lines may pass throughthe voice coil 4238 horizontally and densely to enhance the magneticinduction intensity (or the magnetic field intensity) at the voice coil4238. The sensitivity and the mechanical conversion efficiency of theacoustic output apparatus 4200 (i.e., the efficiency of converting anelectric energy into a mechanical energy of the vibration of the voicecoil 4238) may be improved.

In some embodiments, the magnetic field intensity (or referred to as amagnetic induction intensity or a magnetic induction lines density) ofthe first total magnetic field within the magnetic gap may be greaterthan that of the second magnetic field within the magnetic gap. In someembodiments, the second magnetic component 4208 may generate a thirdmagnetic field, and the third magnetic field may increase the magneticfield intensity of the first total magnetic field within the magneticgap. The third magnetic field increasing the magnetic field intensity ofthe first total magnetic field within the magnetic gap refers to thatthe magnetic field intensity of the first total magnetic field when thethird magnetic field exists (i.e., a magnetic system includes the secondmagnetic component 4208) is greater than that when the third magneticfield doesn't exist (i.e., a magnetic system does not include the secondmagnetic component 4208). As used herein, unless otherwise specified, amagnetic system refers to a system that includes all magneticcomponent(s) and magnetic conductive component(s). The first totalmagnetic field refers to a magnetic field generated by the magneticsystem. Each of the second magnetic field, the third magnetic field, . .. , and the N^(th) magnetic field refers to a magnetic field generatedby a corresponding magnetic component. Different magnetic systems mayunitize a same magnetic component or different magnetic components togenerate the second magnetic field (or the third magnetic field, . . . ,the N^(th) magnetic field).

In some embodiments, an angle (denoted as A1) between the magnetizationdirection of the first magnetic component 4202 and the magnetizationdirection of the second magnetic component 4208 may be in a range from 0degree to 180 degrees. For example, the angle A1 may be in a range from45 degrees to 135 degrees. As another example, the angle A1 may be equalto or greater than 90 degrees. In some embodiments, the magnetizationdirection of the first magnetic component 4202 may be parallel to anupward direction (as indicated by an arrow a in FIG. 42 ) that isperpendicular to the lower surface or the upper surface of the firstmagnetic component 4202. The magnetization direction of the secondmagnetic component 4208 may be parallel to a direction directed from theinner ring to the outer ring of the second magnetic component 4208 (asindicated by an arrow b as shown in FIG. 42 that is on the right side ofthe first magnetic component 4202, which can be obtained by rotating themagnetization direction of the first magnetic component 4202 by 90degrees clockwise). The magnetization direction of the second magneticcomponent 4208 may be perpendicular to that of the first magneticcomponent 4202.

In some embodiments, at the position of the second magnetic component4208, an angle (denoted as A2) between the direction of the first totalmagnetic field and the magnetization direction of the second magneticcomponent 4208 may be not greater than 90 degrees. In some embodiments,at the position of the second magnetic component 4208, an angle (denotedas A3) between the direction of the magnetic field generated by thefirst magnetic component 4202 and the magnetization direction of thesecond magnetic component 4208 may be less than or equal to 90 degrees,such as 0 degree, 10 degrees, or 20 degrees. Compared with a magneticsystem with a single magnetic component, the second magnetic component4208 may increase the total magnetic induction lines within the magneticgap of the magnetic system of the acoustic output apparatus 4200,thereby increasing the magnetic induction intensity within the magneticgap. In addition, due to the second magnetic component 4208, theoriginally scattered magnetic induction lines may be converged to theposition of the magnetic gap, which may further increase the magneticinduction intensity within the magnetic gap.

FIG. 43 is a schematic diagram illustrating a longitudinal sectionalview of an exemplary magnetic system 4300 according to some embodimentsof the present disclosure. As shown in FIG. 43 , different from themagnetic system of the acoustic output apparatus 4200, the magneticsystem 4300 may further include at least one electric conductivecomponent (e.g., a first electric conductive component 4248, a secondelectric conductive component 4250, and a third electric conductivecomponent 4252).

In some embodiments, an electric conductive component may include ametal material, a metal alloy material, an inorganic non-metallicmaterial, or other conductive material. Exemplary metal material mayinclude gold, silver, copper, aluminum, or the like. Exemplary metalalloy material may include an iron-based alloy material, analuminum-based alloy material, a copper-based alloy material, azinc-based alloy material, or the like. Exemplary inorganic non-metallicmaterial may include graphite, or the like. An electric conductivecomponent may have a shape of a sheet, a ring, a mesh, or the like. Thefirst electric conductive component 4248 may be disposed on the uppersurface of the first magnetic conductive component 4204. The secondelectric conductive component 4250 may be mechanically connected to thefirst magnetic component 4202 and the second magnetic conductivecomponent 4206. The third electric conductive component 4252 may bemechanically connected to the side wall of the first magnetic component4202. In some embodiments, the first magnetic conductive component 4204may protrude from the first magnetic component 4202 to form a firstrecess at the right side of the first magnetic component 4202 as shownin FIG. 43 . The third electric conductive component 4252 may bedisposed at the first recess. In some embodiments, the first electricconductive component 4248, the second electric conductive component4250, and the third electric conductive component 4252 may include thesame or different conductive materials.

In some embodiments, a magnetic gap may be formed between the firstmagnetic component 4202, the first magnetic conductive component 4204,and the inner ring of the second magnetic component 4208. The voice coil4238 may be disposed in the magnetic gap. The first magnetic component4202, the first magnetic conductive component 4204, the second magneticconductive component 4206, and the second magnetic component 4208 mayform the magnetic system 4300. In some embodiments, the electricconductive components of the magnetic system 4300 may reduce aninductive reactance of the voice coil 4238. For example, if a firstalternating current is applied to the voice coil 4238, a firstalternating magnetic field may be generated near the voice coil 4238.Under the action of the magnetic field of the magnetic system 4300, thefirst alternating magnetic field may cause the voice coil 4238 togenerate an inductive reactance and hinder the movement of the voicecoil 4238. One or more electric conductive components (e.g., the firstelectric conductive component 4248, the second electric conductivecomponent 4250, and the third electric conductive component 4252)disposed near the voice coil 4238 may induce a second alternatingcurrent under the action of the first alternating magnetic field. Thesecond alternating current induced by the electric conductivecomponent(s) may generate a second alternating induction magnetic fieldin its vicinity. The direction of the second alternating magnetic fieldmay be opposite to that of the first alternating magnetic field, and thefirst alternating magnetic field may be weakened. The inductivereactance of the voice coil 4238 may be reduced, the current in thevoice coil 4238 may be increased, and the sensitivity of the acousticoutput apparatus may be improved.

FIG. 44 is a schematic diagram illustrating a longitudinal sectionalview of an exemplary magnetic system 4400 according to some embodimentsof the present disclosure. As shown in FIG. 44 , different from themagnetic system of the acoustic output apparatus 4200, the magneticsystem 4400 may further include a third magnetic component 4410, afourth magnetic component 4412, a fifth magnetic component 4414, a thirdmagnetic conductive component 4416, a sixth magnetic component 4424, anda seventh magnetic component 4426. In some embodiments, the thirdmagnetic component 4410, the fourth magnetic component 4412, the fifthmagnetic component 4414, the third magnetic conductive component 4416,the sixth magnetic component 4424, and the seventh magnetic component4426 may be coaxial circular cylinders.

In some embodiments, the upper surface of the second magnetic component4208 may be mechanically connected to the seventh magnetic component4426, and the lower surface of the second magnetic component 4208 may bemechanically connected to the third magnetic component 4410. The thirdmagnetic component 4410 may be mechanically connected to the secondmagnetic conductive component 4206. An upper surface of the seventhmagnetic component 4426 may be mechanically connected to the thirdmagnetic conductive component 4416. The fourth magnetic component 4412may be mechanically connected to the second magnetic conductivecomponent 4206 and the first magnetic component 4202. The sixth magneticcomponent 4424 may be mechanically connected to the fifth magneticcomponent 4414, the third magnetic conductive component 4416, and theseventh magnetic component 4426. In some embodiments, the first magneticcomponent 4202, the first magnetic conductive component 4204, the secondmagnetic conductive component 4206, the second magnetic component 4208,the third magnetic component 4410, the fourth magnetic component 4412,the fifth magnetic component 4414, the third magnetic conductivecomponent 4416, the sixth magnetic component 4424, and the seventhmagnetic component 4426 may form a magnetic loop and a magnetic gap.

In some embodiments, an angle (denoted as A4) between the magnetizationdirection of the first magnetic component 4202 and the magnetizationdirection of the sixth magnetic component 4424 may be in a range from 0degree to 180 degrees. For example, the angle A4 may be in a range from45 degrees to 135 degrees. As another example, the angle A4 may be notgreater than 90 degrees. In some embodiments, the magnetizationdirection of the first magnetic component 4202 may be parallel to anupward direction (as indicated by an arrow a in FIG. 44 ) that isperpendicular to the lower surface or the upper surface of the firstmagnetic component 4202. The magnetization direction of the sixthmagnetic component 4424 may be parallel to a direction directed from theouter ring to the inner ring of the sixth magnetic component 4424 (asindicated by an arrow g in FIG. 44 that is on the right side of thefirst magnetic component 4202 after the magnetization direction of thefirst magnetic component 4202 rotates 270 degrees clockwise). In someembodiments, the magnetization direction of the sixth magnetic component4424 may be the same as that of the fourth magnetic component 4412.

In some embodiments, at the position of the sixth magnetic component4424, an angle (denoted as A5) between the direction of a magnetic fieldgenerated by the magnetic system 4400 and the magnetization direction ofthe sixth magnetic component 4424 may be not greater than 90 degrees. Insome embodiments, at the position of the sixth magnetic component 4424,an angle (denoted as A6) between the direction of the magnetic fieldgenerated by the first magnetic component 4202 and the magnetizationdirection of the sixth magnetic component 4424 may be less than or equalto 90 degrees, such as 0 degree, 10 degrees, or 20 degrees.

In some embodiments, an angle (denoted as A7) between the magnetizationdirection of the first magnetic component 4202 and the magnetizationdirection of the seventh magnetic component 4426 may be in a range from0 degree to 180 degrees. For example, the angle A7 may be in a rangefrom 45 degrees to 135 degrees. As another example, the angle A7 may benot greater than 90 degrees. In some embodiments, the magnetizationdirection of the first magnetic component 4202 may be parallel to anupward direction (as indicated by an arrow a in FIG. 44 ) that isperpendicular to the lower surface or the upper surface of the firstmagnetic component 4202. The magnetization direction of the seventhmagnetic component 4426 may be parallel to a direction directed from alower surface to an upper surface of the seventh magnetic component 4426(as indicated by an arrow fin FIG. 44 that is on the right side of thefirst magnetic component 4202 after the magnetization direction of thefirst magnetic component 4202 rotates 360 degrees clockwise). In someembodiments, the magnetization direction of the seventh magneticcomponent 4426 may be opposite to that of the third magnetic component4410.

In some embodiments, at the seventh magnetic component 4426, an angle(denoted as A8) between the direction of the magnetic field generated bythe magnetic system 4400 and the magnetization direction of the seventhmagnetic component 4426 may be not greater than 90 degrees. In someembodiments, at the position of the seventh magnetic component 4426, anangle (denoted as A9) between the direction of the magnetic fieldgenerated by the first magnetic component 4202 and the magnetizationdirection of the seventh magnetic component 4426 may be less than orequal to 90 degrees, such as 0 degree, 10 degrees, or 20 degrees.

In the magnetic system 4400, the third magnetic conductive component4416 may close the magnetic field loops generated by the magnetic system4400, so that more magnetic induction lines may be concentrated in themagnetic gap. This may suppress the magnetic leakage, increase themagnetic induction intensity within the magnetic gap, and improve thesensitivity of the acoustic output apparatus.

FIG. 45 is a schematic diagram illustrating a longitudinal sectionalview of an exemplary magnetic system 4500 according to some embodimentsof the present disclosure. As shown in FIG. 45 , the magnetic system4500 may include a first magnetic component 4502, a first magneticconductive component 4504, a first magnetic field changing component4506, and a second magnetic component 4508.

In some embodiments, an upper surface of the first magnetic component4502 may be mechanically connected to the lower surface of the firstmagnetic conductive component 4504. The second magnetic component 4508may be mechanically connected to the first magnetic component 4502 andthe first magnetic field changing component 4506. Two or more of thefirst magnetic component 4502, the first magnetic conductive component4504, the first magnetic field changing component 4506, and/or thesecond magnetic component 4508 may be connected to each other via amechanical connection as described elsewhere in this disclosure (e.g.,FIG. 42 and the relevant descriptions). In some embodiments, the firstmagnetic component 4502, the first magnetic conductive component 4504,the first magnetic field changing component 4506, and/or the secondmagnetic component 4508 may form a magnetic field loop and a magneticgap.

In some embodiments, the magnetic system 4500 may generate a first totalmagnetic field, and the first magnetic component 4502 may generate asecond magnetic field. The magnetic field intensity of the first totalmagnetic field within the magnetic gap may be greater than that of thesecond magnetic field within the magnetic gap. In some embodiments, thesecond magnetic component 4508 may generate a third magnetic field, andthe third magnetic field may increase the intensity of the magneticfield of the second magnetic field at the magnetic gap.

In some embodiments, an angle (denoted as A10) between the magnetizationdirection of the first magnetic component 4502 and the magnetizationdirection of the second magnetic component 4508 may be in a range from 0degree to 180 degrees. For example, the angle A10 may be in a range from45 degrees to 135 degrees. As another example, the angle A10 may be notgreater than 90 degrees.

In some embodiments, at the position of the second magnetic component4508, an angle (denoted as A11) between the direction of the first totalmagnetic field and the magnetization direction of the second magneticcomponent 4508 may be not greater than 90 degrees. In some embodiments,at the position of the second magnetic component 4508, an angle (denotedas A12) between the direction of the second magnetic field generated bythe first magnetic component 4502 and the magnetization direction of thesecond magnetic component 4508 may be less than or equal to 90 degrees,such as 0 degree, 10 degrees, and 20 degrees. In some embodiments, themagnetization direction of the first magnetic component 4502 may beparallel to an upward direction (as indicated by an arrow a in FIG. 45 )that is perpendicular to the lower surface or the upper surface of thefirst magnetic component 4502. The magnetization direction of the secondmagnetic component 4508 may be parallel to a direction directed from theouter ring to the inner ring of the second magnetic component 4508 (asindicated by an arrow c in FIG. 45 that is on the right side of thefirst magnetic component 4502 after the magnetization direction of thefirst magnetic component 4502 rotates 90 degrees clockwise). Comparedwith a magnetic system with a single magnetic component, the firstmagnetic field changing component 4506 in the magnetic system 4500 mayincrease the total magnetic induction lines within the magnetic gap,thereby increasing the magnetic induction intensity within the magneticgap. In addition, due to the first magnetic field changing component4506, the originally scattered magnetic induction lines may be convergedto the position of the magnetic gap, which may further increase themagnetic induction intensity within the magnetic gap.

FIG. 46 is a schematic diagram illustrating a longitudinal sectionalview of an exemplary magnetic system 4600 according to some embodimentsof the present disclosure. As shown in FIG. 46 , in some embodiments,the magnetic system 4600 may include a first magnetic component 4502, afirst magnetic conductive component 4504, a first magnetic fieldchanging component 4506, a second magnetic component 4508, a thirdmagnetic component 4610, a fourth magnetic component 4612, a fifthmagnetic component 4616, a sixth magnetic component 4618, a seventhmagnetic component 4620, and a second ring component 4622. In someembodiments, the first magnetic field changing component 4506 and/or thesecond ring component 4622 may include a ring-shaped magnetic componentor a ring-shaped magnetic conductive component.

A ring-shaped magnetic component may include any one or more magneticmaterials as described elsewhere in this disclosure (e.g., FIG. 42 andthe relevant descriptions). A ring-shaped magnetic conductive componentmay include any one or more magnetically conductive materials describedin the present disclosure (e.g., FIG. 42 and the relevant descriptions).

In some embodiments, the sixth magnetic component 4618 may bemechanically connected to the fifth magnetic component 4616 and thesecond ring component 4622. The seventh magnetic component 4620 may bemechanically connected to the third magnetic component 4610 and thesecond ring component 4622. In some embodiments, one or more of thefirst magnetic component 4502, the fifth magnetic component 4616, thesecond magnetic component 4508, the third magnetic component 4610, thefourth magnetic component 4612, the sixth magnetic component 4618, theseventh magnetic component 4620, the first magnetic conductive component4504, the first magnetic field changing component 4506, and the secondring component 4622 may form a magnetic field loop.

In some embodiments, an angle (denoted as A13) between the magnetizationdirection of the first magnetic component 4502 and the magnetizationdirection of the sixth magnetic component 4618 may be in a range from 0degree and 180 degrees. For example, the angle A13 may be in a rangefrom 45 degrees to 135 degrees. As another example, the angle A13 may benot greater than 90 degrees. In some embodiments, the magnetizationdirection of the first magnetic component 4502 may be parallel to anupward direction (as indicated by an arrow a in FIG. 46 ) that isperpendicular to the lower surface or the upper surface of the firstmagnetic component 4502. The magnetization direction of the sixthmagnetic component 4618 may be parallel to a direction directed from theouter ring to the inner ring of the sixth magnetic component 4618 (asindicated by an arrow fin FIG. 46 that is on the right side of the firstmagnetic component 4502 after the magnetization direction of the firstmagnetic component 4202 rotates 270 degrees clockwise). In someembodiments, the magnetization direction of the sixth magnetic component4618 may be the same as that of the second magnetic component 4508. Themagnetization direction of the seventh magnetic component 4620 may beparallel to a direction directed from the lower surface to the uppersurface of the seventh magnetic component 4620 (as indicated by an arrowe in FIG. 46 that is on the right side of the first magnetic component4502 after the magnetization direction of the first magnetic component4502 rotates 90 degrees clockwise). In some embodiments, themagnetization direction of the seventh magnetic component 4620 may bethe same as that of the fourth magnetic component 4612.

In some embodiments, at the position of the sixth magnetic component4618, an angle (denoted as A14) between the direction of the magneticfield generated by the magnetic system 4600 and the magnetizationdirection of the sixth magnetic component 4618 may be not greater than90 degrees. In some embodiments, at the position of the sixth magneticcomponent 4618, an angle (denoted as A15) between the direction of themagnetic field generated by the first magnetic component 4502 and themagnetization direction of the sixth magnetic component 4618 may be lessthan or equal to 90 degrees, such as 0 degree, 10 degrees, and 20degrees.

In some embodiments, an angle (denoted as A16) between the magnetizationdirection of the first magnetic component 4502 and the magnetizationdirection of the seventh magnetic component 4620 may be in a range from0 degree and 180 degrees. For example, the angle A16 may be in a rangefrom 45 degrees to 135 degrees. As another example, the angle A16 may benot greater than 90 degrees.

In some embodiments, at the position of the seventh magnetic component4620, an angle (denoted as A17) between the direction of the magneticfield generated by the magnetic system 4600 and the magnetizationdirection of the seventh magnetic component 4620 may be not greater than90 degrees. In some embodiments, at the position of the seventh magneticcomponent 4620, an angle (denoted as A18) between the direction of themagnetic field generated by the first magnetic component 4502 and themagnetization direction of the seventh magnetic component 4620 may beless than or equal to 90 degrees, such as 0 degree, 10 degrees, and 20degrees.

In some embodiments, the first magnetic field changing component 4506may be a ring-shaped magnetic component. The magnetization direction ofthe first magnetic field changing component 4506 may be the same as thatof the second magnetic component 4508 or the fourth magnetic component4612. For example, on the right side of the first magnetic component4502, the magnetization direction of the first magnetic field changingcomponent 4506 may be parallel to a direction directed from the outerring to the inner ring of the first magnetic field changing component4506. In some embodiments, the second ring component 4622 may be aring-shaped magnetic component. The magnetization direction of thesecond ring component 4622 may be the same as that of the sixth magneticcomponent 4618 or the seventh magnetic component 4620. For example, onthe right side of the first magnetic component 4502, the magnetizationdirection of the second ring component 4622 may be parallel to adirection directed from the outer ring to the inner ring of the secondring component 4622. In the magnetic system 4600, the plurality ofmagnetic components may increase the total magnetic induction lines, anddifferent magnetic components may interact, which may suppress theleakage of the magnetic induction lines, increase the magnetic inductionintensity within the magnetic gap, and improve the sensitivity of theacoustic output apparatus.

In some embodiments, the magnetic system 4600 may further include amagnetic conductive cover. The magnetic conductive cover may include oneor more magnetic conductive materials (e.g., low carbon steel, siliconsteel sheet, silicon steel sheet, ferrite, etc.) described in thepresent disclosure. For example, the magnetic conductive cover may bemechanically connected to the first magnetic component 4502, the firstmagnetic field changing component 4506, the second magnetic component4508, the third magnetic component 4610, the fourth magnetic component4612, the fifth magnetic component 4616, the sixth magnetic component4618, the seventh magnetic component 4620, and the second ring component4622. In some embodiments, the magnetic conductive cover may include atleast one bottom plate and a side wall. The side wall may have a ringstructure. The at least one bottom plate and the side wall may form anintegral assembly. Alternatively, the at least one bottom plate may bemechanically connected to the side wall via one or more mechanicalconnections as described elsewhere in the present disclosure. Forexample, the magnetic conductive cover may include a first base plate, asecond base plate, and a side wall. The first bottom plate and the sidewall may form an integral assembly, and the second bottom plate may bemechanically connected to the side wall via one or more mechanicalconnections described elsewhere in the present disclosure.

In the magnetic system 4500, the magnetic conductive cover may close themagnetic field loops_generated by the magnetic system 4500, so that moremagnetic induction lines may be concentrated in the magnetic gap in themagnetic system 4500. This may suppress the magnetic leakage, increasethe magnetic induction intensity at the magnetic gap, and improve thesensitivity of the acoustic output apparatus.

In some embodiments, the magnetic system 4500 may further include one ormore electric conductive components (e.g., a first electric conductivecomponent, a second electric conductive component, and a third electricconductive component). The one or more electric conductive componentsmay be similar to the first electric conductive component 4248, thesecond electric conductive component 4250, and the third electricconductive component 4252 as described in connection with FIG. 43 .

FIG. 47 is a schematic diagram illustrating a longitudinal sectionalview of an exemplary magnetic system 4700 according to some embodimentsof the present disclosure. As shown in FIG. 47 , the magnetic system4700 may include a first magnetic component 4702, a first magneticconductive component 4704, a second magnetic conductive component 4706,and a second magnetic component 4708.

In some embodiments, the first magnetic component 4702 and/or the secondmagnetic component 4708 may include one or more of the magnets describedin the present disclosure. In some embodiments, the first magneticcomponent 4702 may include a first magnet, and the second magneticcomponent 4708 may include a second magnet. The first magnet and thesecond magnet may be the same or different. The first magneticconductive component 4704 and/or the second magnetic conductivecomponent 4706 may include one or more magnetic conductive materialsdescribed in the present disclosure. The first magnetic conductivecomponent 4704 and/or the second magnetic conductive component 4706 maybe manufactured by one or more processing methods described in thepresent disclosure. In some embodiments, the first magnetic component4702, the first magnetic conductive component 4704, and/or the secondmagnetic component 4708 may have an axisymmetric structure. For example,each of the first magnetic component 4702, the first magnetic conductivecomponent 4704, and/or the second magnetic component 4708 may be acylinder. In some embodiments, the first magnetic component 4702, thefirst magnetic conductive component 4704, and/or the second magneticcomponent 4708 may be coaxial cylinders containing the same or differentdiameters. The thickness of the first magnetic component 4702 may begreater than or equal to that of the second magnetic component 4708. Insome embodiments, the second magnetic conductive component 4706 may havea groove-shaped structure. In some embodiments, the groove-shapedstructure may include a U-shaped cross section. The groove-shaped secondmagnetic conductive component 4706 may include a bottom plate and asidewall. In some embodiments, the bottom plate and the side wall mayform an integral assembly. For example, the side wall may be formed byextending the bottom plate in a direction perpendicular to the bottomplate. In some embodiments, the bottom plate may be mechanicallyconnected to the side wall via a mechanical connection as describedelsewhere in this disclosure (e.g., FIG. 42 and the relevantdescriptions). The second magnetic component 4708 may have a shape of aring or a sheet. The shape of the second magnetic component 4708 may besimilar to that of the second magnetic component 4208 as described inconnection with FIG. 43 . In some embodiments, the second magneticcomponent 4708 may be coaxial with the first magnetic component 4702and/or the first magnetic conductive component 4704.

In some embodiments, an upper surface of the first magnetic component4702 may be mechanically connected to a lower surface of the firstmagnetic conductive component 4704. A lower surface of the firstmagnetic component 4702 may be mechanically connected to the bottomplate of the second magnetic conductive component 4706. A lower surfaceof the second magnetic component 4708 may be mechanically connected toan upper surface of the first magnetic conductive component 4704. Two ormore of the first magnetic component 4702, the first magnetic conductivecomponent 4704, the second magnetic conductive component 4706, and/orthe second magnetic component 4708 may be connected to each other via amechanical connection as described elsewhere in this disclosure (e.g.,FIG. 20 and the relevant descriptions).

In some embodiments, a magnetic gap may be formed between the firstmagnetic component 4702, the first magnetic conductive component 4704,the second magnetic component 4708 and a sidewall of the second magneticconductive component 4706. A voice coil 4720 may be disposed in amagnetic gap. In some embodiments, the first magnetic component 4702,the first magnetic conductive component 4704, the second magneticconductive component 4706, and the second magnetic component 4708 mayform a magnetic field loop. In some embodiments, the magnetic system4700 may generate a first total magnetic field, and the first magneticcomponent 4702 may generate a second magnetic field. The first totalmagnetic field may be formed by all magnetic fields generated by allcomponents of the magnetic system 4700 (e.g., the first magneticcomponent 4702, the first magnetic conductive component 4704, the secondmagnetic conductive component 4706, and the second magnetic component4708). The intensity of the magnetic field (or referred to as a magneticinduction intensity or a magnetic induction lines density) within themagnetic gap of the first total magnetic field may be greater than theintensity of the magnetic field within the magnetic gap of the secondmagnetic field. In some embodiments, the second magnetic component 4708may generate a third magnetic field, and the third magnetic field mayincrease the intensity of the magnetic field of the second magneticfield within the magnetic gap.

In some embodiments, an angle (denoted as A19) between the magnetizationdirection of the second magnetic component 4708 and the magnetizationdirection of the first magnetic component 4702 may be in a range from 90degrees and 180 degrees. For example, the angle A10 may be in a rangefrom 150 degrees to 180 degrees. Merely by way of example, themagnetization direction of the second magnetic component 4708 (asindicated by an arrow b in FIG. 47 ) may be opposite to themagnetization direction of the first magnetic component 4702 (asindicated by an arrow a in FIG. 47 ).

Compared with the magnetic system with a single magnetic component, themagnetic system 4700 includes a second magnetic component 4708. Thesecond magnetic component 4708 may have a magnetization directionopposite to that of the first magnetic component 4702, which maysuppress the magnetic leakage of the first magnetic component 4702 inits magnetization direction, so that more magnetic induction linesgenerated by the first magnetic component 4702 may be concentrated inthe magnetic gap, thereby increasing the magnetic induction intensitywithin the magnetic gap.

It should be noted that the above description regarding the magneticsystems is merely provided for the purposes of illustration, and notintended to limit the scope of the present disclosure. For personshaving ordinary skills in the art, multiple variations and modificationsmay be made under the teachings of the present disclosure. However,those variations and modifications do not depart from the scope of thepresent disclosure. In some embodiments, a magnetic system may includeone or more additional components and/or one or more components of theacoustic output apparatus described above may be omitted. Additionallyor alternatively, two or more components of a magnetic system may beintegrated into a single component. A component of the magnetic systemmay be implemented on two or more sub-components.

FIG. 48 illustrates an exploded view of a portion of an acoustic outputapparatus according to some embodiments of the present disclosure. FIG.49 illustrates a cross-sectional view of the portion of the acousticoutput apparatus in FIG. 48 according to some embodiments of the presentdisclosure. As shown in FIG. 48 and FIG. 49 , the acoustic outputapparatus may include a magnetic connector 55. The magnetic connector 55may be used together with a power interface of a charger to charge theacoustic output apparatus. For example, when charging the acousticoutput apparatus, the magnetic connector 55 and the power interface ofthe charger may match each other and be adsorbed together to establishan electrical connection to charge the acoustic output apparatus. Insome embodiments, the magnetic connector 55 may include a magneticadsorption ring 551, an insulation base 552, and a plurality ofterminals (e.g., a first terminal 553, and a second terminal 554).

The magnetic adsorption ring 551 may be a magnet, and the magneticpolarities of an outer end and an inner end may be different. As usedherein, an outer end of a component of an acoustic output apparatusrefers to an end that is closer to the environment of the acousticoutput apparatus (e.g., exposed from the acoustic output apparatus), andan inner end of the component refers to an end that is further from theenvironment of the acoustic output apparatus (e.g., located inside theacoustic output apparatus). The power interface of the charger may havea magnetic adsorption structure that matches the magnetic adsorptionring 551. The magnetic adsorption structure may include one or moremagnetic materials. For example, the magnetic adsorption structure mayinclude iron and/or one or more other materials without polarity, whichmay be adsorbed with the magnetic adsorption ring 551 whether the outerend of the magnetic adsorption ring 551 is the south pole or the northpole. As another example, the magnetic adsorption structure may alsoinclude a magnet and/or one or more other materials with polarity. Themagnetic adsorption ring 551 and the magnetic adsorption structure maybe adsorbed together only when the magnetic polarity of the outer end ofthe magnetic adsorption structure and the magnetic polarity of the outerend of the magnetic adsorption ring 551 are opposite. When the magneticconnector 55 and the power interface are adsorbed with each other, aterminal of the magnetic connector 55 may contact a correspondingterminal of the power interface, and an electrical connection may beestablished between the magnetic connector 55 and the power interface.

The outer end of the magnetic adsorption ring 551 may have any suitableshape. For example, the outer end of the magnetic adsorption ring 551may have a ring shape. The magnetic adsorption ring 551 and the magneticadsorption structure of the power interface may be adsorbed together viathe ring-shaped outer end. Due to the hollow design of the ring-shapedouter end, the magnetic adsorption ring 551 may be adsorbed with thepower interface by magnetic forces in different directions. This mayimprove the stability of the electrical connection between the magneticadsorption ring 551 and the power interface of the charger.

FIG. 50 illustrates a partial enlarged view of a portion A of themagnetic connector 55 in FIG. 49 according to some embodiments of thepresent disclosure. In some embodiments, at least part of the insulationbase 552 may be inserted into the magnetic adsorption ring 551 to fixthe magnetic adsorption ring 551. The insulation base 552 may include atleast two accommodation holes 5521. The at least two accommodation holes5521 may penetrate an outer end of the insulation base 552. In someembodiments, the insulation base 552 may include one or more insulatingmaterials, such as PC or PVC.

A terminal of the magnetic connector 55 may have any suitable shape. Forexample, the first terminal 553 and the second terminal 554 may bothhave a shape of cylinder. The count of the terminals may be equal to thecount of the accommodation holes 5521. Each of the terminals may beinserted into one of the accommodation holes 5521. An outer end of aterminal may be exposed from the top surface of the insulation base 552through the corresponding accommodation hole 5521, that is, the outerend of the terminal may be visible seen from a direction facing the topsurface of the insulation base 552. Optionally, the outer end of aterminal of the magnetic connector 55 may flush with the top surface ofthe insulation base 552 to form a contract surface. For example, asshown in FIG. 50 , the first terminal 553 may form a first contactsurface 5531 and the second terminal 554 may form a second contactsurface 5541. The first terminal 553 and the second terminal 554 maycorrespond to the positive and negative terminals of the powerinterface, respectively. Correspondingly, the first contact surface 5531and the second contact surface 5541 may contact with the power interfaceto establish an electrical connection.

In some embodiments, when the magnetic connector 55 and the powerinterface are adsorbed with each other, the magnetic connector 55 may berestricted by magnetic forces from different directions applied by thehollow ring-shaped the magnetic adsorption ring 551. The first contactsurface 5531 and the second contact surface 5541 may be accuratelypositioned and contact with the power interface to establish anelectrical connection. This may improve the stability and accuracy ofthe electrical connection between the magnetic adsorption ring 551 andthe power interface of the charger.

In some embodiments, the insulation base 552 may include a supportingmember 5522 and an insertion member 5523. The supporting member 5522 andthe insertion member 5523 may be located along a direction parallel toan axis of the accommodation hole 5521. A cross-section of thesupporting member 5522 may be larger than that of the insertion member5523, thereby forming a supporting table 55221 on the supporting member5522 as shown in FIG. 50 .

The outer side wall of the insertion member 5523 may match the innerside wall of the magnetic adsorption ring 551, such that the insertionmember 5523 may be inserted into the magnetic adsorption ring 551 to fixthe magnetic adsorption ring 551. An accommodation hole 5521 of theinsulation base 552 may run through the insertion member 5523 and thesupporting member 5522, such that the terminal accommodated in theaccommodation hole 5521 may run through the entire insulation base 552.For example, the first terminal 553 may run through the entireinsulation base 552. A first end of the first terminal 553 may beexposed from the outer end of the insertion member 5523 to form thefirst contact surface 5531. A second end of the first terminal 553 maybe exposed from the inner end of the supporting member 5522 to connectwith an internal circuit. Similarly, the second terminal 554 may runthrough the entire insulation base 552. A first end of the secondterminal 554 may be exposed from the outer end of the insertion member5523 to form the second contact surface 5541. A second end of the secondterminal 554 may be exposed from the inner end of the supporting member5522 to connect with an internal circuit.

In some embodiments, the insertion member 5523 may be inserted into themagnetic adsorption ring 551, and an inner end of the magneticadsorption ring 551 may be supported by the support table 55221. Thedimension of the magnetic adsorption ring 551 may match that of thesupporting member 5522.

In some embodiments, the magnetic connector 55 may further include ahousing 555. The housing 555 may be sleeved on the insulation base 552and magnetic adsorption ring 551, so that the magnetic connector 55 maybe assembled on the power interface of the acoustic output apparatus asa whole. The housing 555 may include one or more non-magnetic metalmaterials (e.g., copper, aluminum, and/or aluminum alloy), a plasticmaterial, or the like, or any combination thereof.

The housing 555 may include a body 5551 and a flange 5552 located at theouter end of the body 5551. The outer end of the housing 555 may bepartially open due to the flange 5552, and the inner end of the housing555 may be a completely open. The inner surface of the body 5551 maymatch the outer surface of the magnetic member ring 551 and thesupporting member 5522 of the insulation base 552. The flange 5552 maycover the outer end of the magnetic adsorption ring 551. The firstcontact surface 5531 of the first terminal 553 and the second contactsurface 5541 of the second terminal 554 may be exposed for establishingan electrical connection to the power interface.

In some embodiments, the outer end of the insertion member 5523 of theinsulation base 552 may be protruded from the end of the magneticadsorption ring 551 far from the supporting member 5522 as shown in FIG.50 . The shape of the partially opening end formed by the flange 5552may match the shape of the periphery of the insertion member 5523, sothat the end of the insertion member 5523 far from the supporting member5522 may extend through the partially opening end of the housing 555 tothe outside of the housing 555.

In some alternative embodiments, the outer end of the insertion member5523 of the insulation base 552 may be sunken relative to the outer endof the flange 5552.

In some embodiments, the outer peripheral wall of the supporting member5522 and the inner peripheral wall of the body 5551 may be mechanicallyconnected to each other via a buckle connection. The buckle connectionmay improve the stability of the mechanical connection between thehousing 555, the insulation base 552, and the magnetic adsorption ring551, thereby improving the stability of the magnetic connector 55.

In some embodiments, two through grooves 55511 may be located on twoopposite surfaces of the outer peripheral wall of the body 5551,respectively. The supporting member 5522 may include two buckles 55222matching the two through grooves 55511. The housing 555 may be sleevedon the supporting member 5522 of the insulation base 552 via the buckleconnections between the through grooves 55511 and the buckles 55222.

In some embodiments, the outer end of the magnetic adsorption ring 551may be rotationally symmetrical with respect to a preset symmetry point(or referred to as a rotation center). When the magnetic adsorption ring551 rotates, the first contact surface 5531 and the second contactsurface 5541 may rotate together with the magnetic adsorption ring 551.The first contact surface 5531 and the second contact surface 5541before rotating may at least partially overlap the first contact surface5531 and the second contact surface 5541 after rotating. That is, thesurface formed by the first contact surface 5531 and the second contactsurface 5541 may be or close to rotationally symmetrical with respect tothe same preset symmetry point. The shape of the outer end of themagnetic adsorption ring 551 and the angle of rotation symmetry may bedetermined based on the arrangement of the first contact surface 5531and the second contact surface 5541. For example, the outer end of themagnetic adsorption ring 551 may have a shape of a circular ring, anelliptical ring, a rectangular ring, etc.

Due to the rotationally symmetrical shape of the outer end of themagnetic adsorption ring 551, the magnetic adsorption ring 551 may bemoved back to its original position after a symmetrical rotation. Themagnetic adsorption ring 551 may have at least two assembly positionsrelative to the first contact surface 5531 and the second contactsurface 5541, and the magnetic connector 55 and the power interface maybe adsorbed with each other at a plurality of rotation angles toestablish an electrical connection.

In some embodiments, as shown in FIG. 51 , the outer end of the magneticadsorption ring 551 may have a shape of a circular ring with the centeras the symmetry point. The first contact surface 5531 and the secondcontact surface 5541 may respectively have a shape of a circular or acircular ring concentrically arranged with the magnetic adsorption ring551. When the magnetic adsorption ring 551 rotates symmetrically at anyangle with respect to the symmetry point, both the first contact surface5531 and the second contact surface 5541 before rotating may completelyoverlap the first contact surface 5531 and the second contact surface5541 after rotating. When the magnetic adsorption ring 551 absorbs acorresponding magnetic adsorption structure of the power interface, thefirst contact surface 5531 and the second contact surface 5541 may becorresponding to a positive terminal and a negative terminal of thepower interface, respectively, and the magnetic connector 55 and thepower interface may be adsorbed with each other without furthercalibration, which is convenient for users.

In some embodiments, as shown in FIG. 52 , the count of the firstcontact surface 5531 may be one, and the count of the second contactsurface 5541 may be one. The first contact surface 5531 and the secondcontact surface 5541 may be arranged in a 180 degrees rotationallysymmetrical shape with respect to the symmetry point. When the magneticadsorption ring 551 rotates 180 degrees, the first contact surface 5531after rotating may completely overlap the second contact surface 5541before rotating, and the second contact surface 5541 after rotating maycompletely overlap the first contact surface 5531 before rotating. Thefirst contact surface 5531 and the second contact surface 5541 may bearranged side by side and corresponding to a positive terminal and anegative terminal of the power interface, respectively. The outer end ofthe magnetic adsorption ring 551 may have a 180 degrees rotationallysymmetrical shape with respect to a symmetry point.

As shown in FIG. 53 , the outer end of the magnetic adsorption ring 551may have a 180 degrees rotationally symmetrical shape with respect tothe symmetry point. When the magnetic adsorption ring 551 rotates 180degrees, the first contact surface 5531 and the second contact surface5541 before rotating may at least partially overlap the first contactsurface 5531 and the second contact surface 5541 after rotating,respectively. The dimension of the magnetic adsorption ring 551 in afirst direction may be different from that in a second directionperpendicular to the first direction. For example, the outer end of themagnetic adsorption ring 551 may have a shape of an elliptical ring, arectangular ring, or the like.

In some embodiments, the dimension of the magnetic adsorption ring 551in the first direction may be greater than that in the second direction.The count of the first contact surface 5531 may be one, and the firstcontact surface 5531 may be located at the symmetry point of themagnetic adsorption ring 551. The count of the second contact surface5541 may be two, and the two second contact surfaces 5541 may beequidistantly located at both sides of the symmetry point of themagnetic adsorption ring 551 in the first direction. When the magneticadsorption ring 551 rotates 180 degrees, the two second contact surfaces5541 may swap positions with each other. The shape of the first contactsurface 5531 may be the same as or different from that of the secondcontact surfaces 5541. The shapes of the two second contact surfaces5541 may be the same. For example, the first contact surface 5531 andthe second contact surfaces 5541 may both have a circular shape, oranother shape that can be completely overlapped after being rotated 180degrees around the symmetry point.

When the magnetic adsorption ring 551 rotates 180 degrees, the magneticadsorption ring 551 may be in two opposite directions, and the firstcontact surface 5531 and the second contact surface(s) 5541 may at leastpartially overlap each other after 180-degrees rotation. In such cases,the magnetic adsorption ring 551 may have two assembly positions. Ateach of the two assembly positions, the magnetic adsorption ring 551 maybe sleeved on the insertion member 5523 of the insulation base 552 whichis provided with the first terminal 553 and the second terminal 554, andthe magnetic connector 55 and the power interface may be adsorbed witheach other to establish an electrical connection.

In some embodiments, the magnetic adsorption ring 551 may be dividedinto at least two ring sections 5511 in the circumferential direction.The outer ends of the adjacent ring sections 5511 may have differentmagnetic polarities. The division of ring section 5511 may be performedaccording to a certain rule. For example, if the outer end of themagnetic adsorption ring 551 has an annular shape, the magneticadsorption ring 551 may be equally divided along its radial direction.Merely by way of example, the magnetic adsorption ring 551 may bequartered into four ring sections 5511 with the same shape. As anotherexample, the magnetic adsorption ring 551 may be divided randomly. Asanother example, if the outer end of the magnetic adsorption ring 551has a shape of a regular symmetrical ring such as an oval ring, a circlering, or a rectangular ring, the magnetic adsorption ring 551 may beequally divided into two or more ring sections 5511 along at least onesymmetry axis of the magnetic adsorption ring 551. If the outer end ofthe magnetic adsorption ring 551 has a shape of an irregular ring, themagnetic adsorption ring 551 may be divided into two or moreasymmetrical ring sections 5511.

The magnetic polarity of the outer end of each ring section 5511 may bedetermined according to the connection between the contract surface(s)(e.g., the first contact surface 5531 and/or the second contact surface5541) and the terminal(s) of the power interface. The connection betweenthe contract surface(s) (e.g., the first contact surface 5531 and/or thesecond contact surface 5541) and the terminal(s) of the power interfacemay include a valid connection and an invalid connection. As usedherein, a valid connection refers to a connection that the contractsurface(s) (e.g., the first contact surface 5531 and/or the secondcontact surface 5541) may be adsorbed with the terminal(s) of the powerinterface, and the magnetic polarity of the outer end of each ringsection 5511 may be opposite to that of the outer end of a correspondingmagnetic adsorption structure of the power interface. A invalidconnection refers to a connection that the contract surface(s) (e.g.,the first contact surface 5531 and/or the second contact surface 5541)cannot be adsorbed with the terminal(s) of the power interface becausethe magnetic polarity of the outer end of each ring section 5511 may bethe same as that of the outer end of a corresponding magnetic adsorptionstructure of the power interface. The valid connection may establish anelectrical connection between the magnetic connector 55 and the powerinterface to charge the acoustic output apparatus. The invalidconnection cannot establish an electrical connection between themagnetic connector 55 and the power interface to charge the acousticoutput apparatus.

In some embodiments, the dimension of the magnetic adsorption ring 551in a first direction may be different from that in a second directionperpendicular to the first direction. For example, the dimension of themagnetic adsorption ring 551 in the first direction may be greater thanthat in the second direction. Merely by way of example, the outer end ofthe magnetic adsorption ring 551 may have a shape of an elliptical ring.In some embodiments, the magnetic adsorption ring 551 may be dividedinto two ring sections 5511 arranged side by side along a symmetry axisof the elliptical ring in the first direction or the second direction.The magnetic polarity of the outer end face of one ring section 5511 maybe N pole, and the magnetic polarity of the outer end face of the otherring section 5511 may be S pole. In some embodiments, the first contactsurface 5531 and the second contact surface 5541 may be arranged in a180 degrees rotationally symmetrical shape with respect to the symmetrypoint.

A shape and a count of the magnetic adsorption structure(s) of the powerinterface may be the same as that of the magnetic adsorption ring 551 ofthe magnetic connector 55. The magnetic polarity of the outer end of amagnetic adsorption structure of the power interface may be opposite tothat of the outer end of a corresponding ring section 5511 of themagnetic adsorption ring 551. If a connection between the contractsurface(s) (e.g., the first contact surface 5531 and/or the secondcontact surface 5541) and the terminal(s) of the power interface is avalid connection, a ring section 5511 of the magnetic adsorption ring551 may be adsorbed with a corresponding magnetic adsorption structureof the power interface to establish an electrical connection to chargethe acoustic output apparatus. If a connection between the contractsurface(s) (e.g., the first contact surface 5531 and/or the secondcontact surface 5541) and the terminal(s) of the power interface is aninvalid connection, a ring section 5511 of the magnetic adsorption ring551 cannot be adsorbed with a corresponding magnetic adsorptionstructure of the power interface. This may avoid an invalid connectionbetween the magnetic connector 55 and the power interface and isconvenient for users.

The present disclosure may also provide a magnetic connector component,which includes two magnetic connectors 55 as described in the presentdisclosure. For example, the magnetic connector component may include amagnetic connector 55 a and a magnetic connector 55 b. A shape and acount of the ring section(s) 5511 of the magnetic adsorption ring 551 ofthe magnetic connector 55 a may be the same as that of the magneticconnector 55 b. A magnetic polarity of the ring section(s) 5511 of themagnetic adsorption ring 551 of the magnetic connector 55 a may beopposite to that of the magnetic connector 55 b. When the magneticconnectors 55 a and 55 b absorb each other, the contract surface(s) ofthe magnetic connector 55 a may contact the contract surface(s) of themagnetic connector 55 b. The connection between the magnetic connector55 a and the magnetic connector 55 b may be the same as or similar tothat between the magnetic connector 55 and the power interface asdescribed in connection with FIGS. 51-53 . For example, when a firstcontact surface 5531 and a second contact surface 5541 of the magneticconnector 55 a contact with a first contact surface 5531 and a secondcontact surface 5541 of the magnetic connector 55 b, the magneticconnector 55 a and the magnetic connector 55 b may be adsorbed togetherto establish a valid connection if their ring sections have oppositemagnetic polarities. When the first contact surface 5531 and the secondcontact surface 5541 of the magnetic connector 55 a contact with thefirst contact surface 5531 and the second contact surface 5541 of themagnetic connector 55 b, the magnetic connector 55 a and the magneticconnector 55 b cannot be adsorbed together if their ring sections havethe magnetic polarity. This may avoid an invalid connection between themagnetic connector 55 a and the magnetic connector 55 b and isconvenient for users.

In some embodiments, as shown in FIG. 48 and FIG. 49 , the magneticconnector 55 may be mounted in a circuit housing 10. The circuit housing10 may include two main side walls 11 spaced from each other and atleast one end wall 13. An inner surface of at least one main side wall11 may include two blocking walls 19 spaced from each other. The twoblocking walls 19 may be arranged in parallel with an end wall 13 of thecircuit housing 10. The two main side walls 11 and the two blockingwalls 19 may form an accommodating space near a secondary side wall 12,and the magnetic connector 55 may be located in the accommodating space.

In some embodiments, each of the two main side walls 11 may furtherinclude a mounting hole 113. The acoustic output apparatus may furtherinclude two fixing components 56. The two fixing components 56 may beinserted into the mounting holes 113 of the two main side walls 11,respectively, and fix the magnetic connector 55. The count of themounting holes 113 and the count of the fixing components 56 may be thesame. Merely by way of example, a fixing component 56 may be a screw. Anend of the screw may pass through a mounting hole 113 of a main sidewall 11 to abut against the outer side wall of the magnetic connector55, and the other end of the screw may be fixed in the mounting hole113.

In some embodiments, each of the opposite sides of the magneticconnector 55 may include two mounting holes 55512 for receiving thefixing components 56. The magnetic connector 55 may have a 180 degreesrotationally symmetrical structure with respect to a symmetry axisparallel to a direction the magnetic connector 55 along which it isinserted into the accommodating space. After the magnetic connector 55is inserted into the accommodating space, at least one of the twomounting holes 55512 of each of the opposite sides of the magneticconnector 55 may be aligned with a mounting hole 113. The mounting hole113 may be configured to receive an outer end of a fixing component 56.The mounting hole 55512 may be configured to receive an inner end of thefixing component 56. The two ends of the fixing component 56 may runthrough the mounting hole 113 and the mounting hole 55512, respectively,to fix the magnetic connector 55 in the accommodating space. In someembodiments, the magnetic connector 55 may have 180 degrees rotationallysymmetrical shape, and include two mounting holes 55512 on its sidesurface as shown in FIG. 48 and two mounting holes 55512 on a surfaceopposite to the side surface. In this way, there are two mounting holesmatching the mounting holes 113 no matter whether the magnetic connector55 is rotated or not, which may facilitate the mounting of the magneticconnector 55.

A first housing protective casing 21 and/or a second housing protectivecasing 31 may cover the mounting hole(s) 113 of the main side wall 11.The first housing protective casing 21 and/or the second housingprotective casing 31 may include an exposing hole 57 for the magneticconnector 55 to be exposed, which may facilitate the use of the acousticoutput apparatus.

It should be noted that the above description regarding the acousticoutput apparatus is merely provided for the purposes of illustration,and not intended to limit the scope of the present disclosure. Forpersons having ordinary skills in the art, multiple variations andmodifications may be made under the teachings of the present disclosure.However, those variations and modifications do not depart from the scopeof the present disclosure. In some embodiments, the acoustic outputapparatus may include one or more additional components and/or one ormore components of the acoustic output apparatus described above may beomitted. Additionally or alternatively, two or more components of theacoustic output apparatus may be integrated into a single component. Acomponent of the acoustic output apparatus may be implemented on two ormore sub-components.

What is claimed is:
 1. An acoustic output apparatus, comprising: aspeaker assembly including at least one acoustic driver, the at leastone acoustic driver being configured to output a first sound with afirst frequency range from a pair of first sound guiding holes andoutput a second sound with a second frequency range from a pair ofsecond sound guiding holes, wherein the second frequency range includesfrequencies higher than the first frequency range, the first frequencyrange and the second frequency range overlap each other, the first soundguiding holes are spaced apart from each other by a first distance, thesecond guiding holes are spaced apart from each other by a seconddistance, the first distance is greater than the second distance; and asupporting structure for supporting the speaker assembly proximate tobut not blocking a user's ear canal.
 2. The acoustic output apparatus ofclaim 1, further comprising: a first acoustic route between the at leastone acoustic driver and the pair of first sound guiding holes; and asecond acoustic route between the at least one acoustic driver and thepair of second sound guiding holes, wherein the first acoustic route andthe second acoustic route have different frequency selectioncharacteristics.
 3. The acoustic output apparatus of claim 1, furthercomprising: a magnetic connector configured to charge the acousticoutput apparatus when the magnetic connector absorbs a charginginterface of an external power source.
 4. The acoustic output apparatusof claim 3, wherein the magnetic connector comprises: a magneticadsorption ring; an insulation base including a plurality ofaccommodation holes, at least part of the insulation base being insertedinto the magnetic adsorption ring; and a plurality of terminals each ofwhich is accommodated in one of the plurality of accommodation holes. 5.The acoustic output apparatus of claim 1, wherein the supportingstructure comprises an ear hook that connects to the speaker assemblyand hangs the speaker assembly before the user's ear canal.
 6. Theacoustic output apparatus of claim 1, wherein the supporting structurecomprises a headband placed over a head of a user when the acousticoutput apparatus is worn by the user.
 7. The acoustic output apparatusof claim 1, wherein the first distance is in a range from 20 mm to 40 mmand the second distance is in a range from 3 mm to 7 mm.
 8. The acousticoutput apparatus of claim 1, wherein the at least one acoustic drivercomprises: a first acoustic driver configured to output the first sound;and a second acoustic driver configured to output the second sound. 9.The acoustic output apparatus of claim 8, wherein at least one of thepair of second sound guiding holes is closer to the user's ear canalthan at least one of the pair of first sound guiding holes.
 10. Theacoustic output apparatus of claim 8, wherein the speaker assemblycomprises: a first housing for accommodating the first acoustic driver;and a second housing for accommodating the second acoustic driver. 11.The acoustic output apparatus of claim 10, wherein: the first housingincludes a first chamber and a second chamber located on either side ofthe first acoustic driver, the first chamber being acoustically coupledto one of the pair of first sound guiding holes, the second chamberbeing acoustically coupled to other one of the pair of first soundguiding holes.
 12. The acoustic output apparatus of claim 11, wherein:the second housing includes a third chamber and a fourth chamber locatedon either side of the second acoustic driver, the third chamber beingacoustically coupled to one of the pair of second sound guiding holes,the fourth chamber being acoustically coupled to other one of the pairof second sound guiding holes.
 13. The acoustic output apparatus ofclaim 8, wherein: the first sound includes a first portion outputtedfrom one of the pair of first sound guiding holes and a second portionoutputted from other one of the pair of first sound guiding holes, thefirst portion having an inversed phase with respect to the secondportion.
 14. The acoustic output apparatus of claim 8, wherein the firstfrequency range includes frequencies below 650 Hz and the secondfrequency range includes frequencies above 1000 Hz.
 15. The acousticoutput apparatus of claim 8, wherein the acoustic output apparatusfurther comprises: a control device configured to control the firstacoustic driver and the second acoustic driver, the control devicecomprising a frequency division module configured to divide a sourcesignal into: a low-frequency signal corresponding to the first frequencyrange for driving the first acoustic driver to output the first sound;and a high-frequency signal corresponding to the second frequency rangefor driving the second acoustic driver to output the second sound. 16.The acoustic output apparatus of claim 15, wherein the frequencydivision module comprises at least one of a passive filter, an activefilter, an analog filter, or a digital filter.
 17. The acoustic outputapparatus of claim 8, wherein: the first acoustic driver comprises afirst electro-acoustic transducer, the second acoustic driver comprisesa second electro-acoustic transducer, and the first electro-acoustictransducer and the second electro-acoustic transducer have differentfrequency responses.
 18. The acoustic output apparatus of claim 1,wherein the at least one acoustic driver comprises: a magnetic systemfor generating a first magnetic field, the magnetic system comprising: afirst magnetic component for generating a second magnetic field; and atleast one second magnetic component surrounding the first magneticcomponent, a magnetic gap being formed between the first magneticcomponent and the at least one second magnetic component, a magneticfield intensity of the first magnetic field in the magnetic gap beinggreater than a magnetic field intensity of the second magnetic field inthe magnetic gap.
 19. The acoustic output apparatus of claim 18, whereinthe magnetic system further comprises: a first magnetic conductivecomponent mechanically connected to a first surface of the firstmagnetic component.